tag:theconversation.com,2011:/africa/topics/moon-606/articlesMoon – The Conversation2024-03-27T17:09:15Ztag:theconversation.com,2011:article/2258662024-03-27T17:09:15Z2024-03-27T17:09:15ZThe April 8 eclipse provides a rare opportunity to witness the sun’s superhot corona<figure><img src="https://images.theconversation.com/files/584383/original/file-20240326-16-cpzqx3.jpg?ixlib=rb-1.1.0&rect=0%2C2%2C1888%2C1057&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The corona of the sun can be clearly seen in this image taken in 2007.</span> <span class="attribution"><a class="source" href="https://images.nasa.gov/details/PIA09320">(NASA/JPL-Caltech/NRL/GSFC)</a></span></figcaption></figure><p>Being within a narrow path across Mexico, the United States and eastern Canada on April 8 will give a rare chance to see the hottest thing any human ever sees: the corona surrounding the sun.</p>
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Read more:
<a href="https://theconversation.com/on-april-8-2024-parts-of-ontario-quebec-the-maritimes-and-newfoundland-will-see-a-total-eclipse-of-the-sun-heres-how-to-get-ready-for-it-203382">On April 8, 2024, parts of Ontario, Québec, the Maritimes and Newfoundland will see a total eclipse of the sun. Here's how to get ready for it.</a>
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<p>The word “corona” means “crown” — during the eclipse, it becomes visible, and streaming plasma leaving the sun appears in amazing patterns.</p>
<p>This outer atmosphere shines with a strange whitish light, and is safe to look at once the bright surface of the sun is fully obscured. However, it is not safe to look at partial phases of the eclipse without <a href="https://theconversation.com/total-solar-eclipses-while-stunning-can-damage-your-eyes-if-viewed-without-the-right-protection-221381">suitable eye protection</a> such as an approved filter or a <a href="https://svs.gsfc.nasa.gov/14391/">shadow box</a>. </p>
<p>Humankind has been awed by this spectacle <a href="https://www.wired.com/2008/05/may-28-585-bc-predicted-solar-eclipse-stops-battle/">for a very long time without understanding it</a>. Astronomers now know the sun’s corona is heated to up to <a href="https://www.nasa.gov/science-research/heliophysics/nasas-parker-solar-probe-and-the-curious-case-of-the-hot-corona/">two million degrees Kelvin</a>, numerically almost equivalent to Celsius for such high temperatures. </p>
<p>What astronomers haven’t figured out yet is why the corona is so hot.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/ykkrf87WsLI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA scientists describe photographing the sun’s corona during the 2015 eclipse.</span></figcaption>
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<h2>Heat and density</h2>
<p>The surface of the sun has a temperature of <a href="https://scied.ucar.edu/learning-zone/sun-space-weather/surface-of-the-sun">only about 5,800 kelvins</a> (5,500 C). The reason that we can safely look at the corona but must avoid looking at the surface has to do with density: <a href="https://spaceplace.nasa.gov/sun-corona/en/">the corona is very thin</a>, and most of the light we see is reflected sunlight from the surface. </p>
<p>The sun’s surface has enough density that, at its temperature, it emits about <a href="https://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-radiation-in-space">65 megawatts for each square meter</a>. Even diluted by <a href="https://earthsky.org/space/what-is-the-astronomical-unit/">distance from the sun of 150 million kilometres</a>, this is enough to cause immediate eye damage.</p>
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Read more:
<a href="https://theconversation.com/total-solar-eclipses-while-stunning-can-damage-your-eyes-if-viewed-without-the-right-protection-221381">Total solar eclipses, while stunning, can damage your eyes if viewed without the right protection</a>
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<p>Since the corona is such thin gas, despite its high temperature, it does not emit nor reflect much light. For this reason, we can see it only when the body of the sun is completely blocked by the moon. Otherwise the scattered light in our atmosphere completely overwhelms it.</p>
<p>The mystery of the corona’s heat <a href="https://www.americanscientist.org/article/revealing-the-true-solar-corona">puzzled 19th-century astronomers</a>. At the time, new instruments had been developed to study <a href="https://www.azooptics.com/Article.aspx?ArticleID=1984">the composition of celestial bodies</a>.</p>
<p>In 1704, Sir Isaac Newton had discovered that “white” light could be split into colors, a result <a href="https://library.si.edu/digital-library/book/optickstreatise00newta">published in <em>Opticks</em></a>. Unfortunately, his basic views about light were wrong and likely set back the development of optical science 100 years! </p>
<p>Only in the early 1800s were instruments developed, largely setting the stage for the <a href="https://www.zeiss.com/corporate/en/about-zeiss/past/history/locations.html">immensely profitable German optical industry</a>. This allowed scientists to find out what materials were made of by the light they emitted when heated. </p>
<p>A staple of such studies was the <a href="https://www.britannica.com/science/Bunsen-burner">Bunsen burner</a>, originally developed not to have a colour like other flames do.</p>
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<a href="https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a black circle surrounded by wispy white light against a navy background" src="https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=540&fit=crop&dpr=1 754w, https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=540&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/582669/original/file-20240318-16-fmoksh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=540&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A total solar eclipse in 2015 over Svalbard, Norway, reveals the streaming shapes in the solar wind pillars.</span>
<span class="attribution"><span class="source">(M. Druckmüller, S. Habbal, P. Aniol, P. Štarha)</span></span>
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<h2>Photography and astrophysics</h2>
<p>The parallel development of photography also helped <a href="https://history.aip.org/exhibits/cosmology/tools/tools-spectroscopy.htm">astronomy to turn into the science of astrophysics</a>, and the sun was an ideal first target for early instruments due to being very bright. </p>
<p>During the solar eclipse of 1868, emissions like the bright red known to be <a href="https://skyandtelescope.org/observing/guide-to-observing-the-sun-in-h-alpha092321050923/">from hydrogen were observed</a>. But when this light was broken down with a spectroscope, it also showed a yellow light that had never been observed on Earth. </p>
<p>This was determined to be a new element, named for its association with the sun (Greek <em>helios</em>). Only in 1895 was helium found on Earth, and in the strangest of places: <a href="https://www.smithsonianmag.com/history/how-scientists-discovered-helium-first-alien-element-1868-180970057/">radioactive ores</a>. </p>
<p>Almost all helium now used on Earth comes from natural gas fields, where it is trapped as it comes up from uranium and other decaying radioactive ores. The helium in the sun later became strong evidence for the Big Bang, in which the first nuclei, which were hydrogen, quickly underwent nuclear fusion to produce helium, but its discovery in the sun set the stage for expecting new elements there.</p>
<h2>A new mystery</h2>
<p>Once spectroscopy developed further in the late 19th century, indeed another mystery arose. Many elements had been discovered on Earth and put in systematic order by Russian chemist Dmitri Mendeleev as the “<a href="https://pubchem.ncbi.nlm.nih.gov/periodic-table">periodic table</a>.”</p>
<p>Surprisingly, many elements were also detected in solar spectra, usually when they absorbed specific wavelengths from the pure light coming from deep layers in the sun, <a href="https://imagine.gsfc.nasa.gov/science/toolbox/spectra1.html">leaving absorption lines</a>. Although the sun is made mostly of hydrogen and helium, these are not prominent in its spectrum. </p>
<p>However, in the corona, completely unknown lines were found. Following the lead of helium, it was felt that the sun must contain an element never observed on Earth, <a href="https://sunearthday.nasa.gov/2006/locations/coronium.php">promptly dubbed coronium</a>. Only in the 1940s was it realized that the emissions actually came from familiar elements, including iron. These were not initially recognized due to being highly stripped of the normal number of electrons going around their nuclei (normally 26 in iron), indicating extreme temperatures that rip atoms apart. </p>
<p>Even stranger, the further out one observed from the sun, the hotter the corona became.</p>
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<a href="https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a black circle surrounded by wisps of red and green" src="https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/582445/original/file-20240318-20-t6q0rt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The 2015 eclipse imaged in the light given off by highly ionized iron. The red indicates a temperature about one million degrees C, green about two million degrees C.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.3847/2041-8213/abe775">(SOURCE)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<h2>Solar winds and weather</h2>
<p>In the late 1950s, the physicist Eugene Parker found that such high temperatures for the solar corona meant that it could not be static: it had to <a href="https://news.uchicago.edu/explainer/what-is-solar-wind">be blowing off into space</a>. This prediction was verified by <a href="http://www.phy6.org/Education/whsolwi.html">spacecraft measurements in 1959</a>. </p>
<p>Since then, we have known that there is a solar wind, and that the magnetic field shown by coronal structures is carried off into space with it. The solar wind can bring energy to Earth, which penetrates near us when the magnetic field is opposed to that of our planet, bringing auroras and potentially hazardous “<a href="https://theconversation.com/space-weather-is-difficult-to-predict-with-only-an-hour-to-prevent-disasters-on-earth-159895">space weather</a>.”</p>
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Read more:
<a href="https://theconversation.com/larger-and-more-frequent-solar-storms-will-make-for-potential-disruptions-and-spectacular-auroras-on-earth-219183">Larger and more frequent solar storms will make for potential disruptions and spectacular auroras on Earth</a>
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<p>NASA’s <a href="https://science.nasa.gov/mission/parker-solar-probe/">Parker Solar Probe</a> is now nearing the inner regions of the corona, still trying to determine the exact origins of the solar wind. Parker, who passed away in 2022, saw initial results from this spacecraft trying to find exactly how the outrageously hot corona propels the solar wind. </p>
<p>Meanwhile, April 8 is a rare opportunity to safely view the sun’s glorious super-heated corona.</p><img src="https://counter.theconversation.com/content/225866/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Connors receives funding from NSERC. </span></em></p>The solar corona can be seen during the solar eclipse on April 8. Astronomers are still trying to figure out the mysteries of the corona, including why it’s so hot.Martin Connors, Professor of Space Science and Physics, Athabasca UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2265582024-03-27T17:07:01Z2024-03-27T17:07:01ZThe total solar eclipse in North America could help shed light on a persistent puzzle about the Sun<figure><img src="https://images.theconversation.com/files/584141/original/file-20240325-24-ot473c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/totality-during-2023-australian-total-solar-2344355767">aeonWAVE / Shutterstock</a></span></figcaption></figure><p>A <a href="https://science.nasa.gov/eclipses/types/#hds-sidebar-nav-1">total solar eclipse</a> takes place on <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/">April 8 across North America</a>. These events occur when the Moon passes between the Sun and Earth, completely blocking the Sun’s face. This plunges observers into a darkness similar to dawn or dusk.</p>
<p>During the upcoming eclipse, the path of totality, where observers experience the darkest part of the Moon’s shadow (the umbra), crosses Mexico, arcing north-east through Texas, the Midwest and briefly entering Canada before ending in Maine.</p>
<p>Total solar eclipses occur roughly <a href="https://www.nhm.ac.uk/discover/solar-eclipse-guide.html">every 18 months at some location on Earth</a>. The last total solar eclipse that crossed the US took place on August 21 2017. </p>
<p>An international team of scientists, led by Aberystwyth University, will be conducting experiments from <a href="https://www.fox4news.com/news/2024-eclipse-dallas-crowds-traffic">near Dallas</a>, at a location in the path of totality. The team consists of PhD students and researchers from Aberystwyth University, Nasa Goddard Space Flight Center in Maryland, and Caltech (California Institute of Technology) in Pasadena. </p>
<p>There is valuable science to be done during eclipses that is comparable to or better than what we can achieve via space-based missions. Our experiments may also shed light on a longstanding puzzle about the outermost part of the Sun’s atmosphere – its corona.</p>
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<img alt="Eclipse shadow" src="https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584503/original/file-20240326-18-9yqs13.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The path of eclipse totality passes through Mexico, the US and Canada.</span>
<span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/5186/">NASA's Scientific Visualization Studio</a></span>
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<p>The Sun’s intense light is blocked by the Moon during a total solar eclipse. This means that we can observe the <a href="https://solarscience.msfc.nasa.gov/corona.shtml">Sun’s faint corona</a> with incredible clarity, from distances very close to the Sun, out to several solar radii. One radius is the distance equivalent to half the Sun’s diameter, about 696,000km (432,000 miles).</p>
<p>Measuring the corona is extremely difficult without an eclipse. It requires a special telescope <a href="https://www.space.com/what-is-a-coronagraph.html">called a coronagraph</a> that is designed to block out direct light from the Sun. This allows fainter light from the corona to be resolved. The clarity of eclipse measurements surpasses even coronagraphs based in space.</p>
<p>We can also observe the corona on a relatively small budget, compared to, for example, spacecraft missions. A persistent puzzle about the corona is the observation <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1002/9781119815600.ch2">that it is much hotter</a> than the photosphere (the visible surface of the Sun). As we move away from a hot object, the surrounding temperature should decrease, not increase. How the corona is heated to such high temperatures is one question we will investigate.</p>
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<img alt="Solar eclipse." src="https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584507/original/file-20240326-20-xairh2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/solar-eclipse-diagram-1146598682">Andramin / Shutterstock</a></span>
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<p>We have two main scientific instruments. The first of these is Cip (coronal imaging polarimeter). Cip is also the Welsh word for “glance”, or “quick look”. The instrument takes images of the Sun’s corona with a polariser. </p>
<p>The light we want to measure from the corona is highly polarised, which means it is made up of waves that vibrate in a single geometric plane. A polariser is a filter that lets light with a particular polarisation pass through it, while blocking light with other polarisations. </p>
<p>The Cip images will allow us to measure fundamental properties of the corona, such as its density. It will also shed light on phenomena such as the solar wind. This is a stream of sub-atomic particles in the form of plasma – superheated matter – flowing continuously outward from the Sun. Cip could help us identify sources in the Sun’s atmosphere for certain solar wind streams.</p>
<p>Direct measurements of the magnetic field in the Sun’s atmosphere are difficult. But the eclipse data should allow us to study its fine-scale structure and trace the field’s direction. We’ll be able to see how far magnetic structures called large “closed” magnetic loops extend from the Sun. This in turn will give us information about large-scale magnetic conditions in the corona.</p>
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<img alt="Coronal loops." src="https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=442&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=442&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=442&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=555&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=555&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584489/original/file-20240326-24-zlpsmc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=555&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Coronal loops are found around sunspots and in active regions of the Sun.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/image-article/coronal-loops-an-active-region-of-sun/">NASA/Solar Dynamics Observatory</a></span>
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<p>The second instrument is Chils (coronal high-resolution line spectrometer). It collects high-resolution spectra, where light is separated into its component colours. Here, we are looking for a particular spectral signature of iron emitted from the corona. </p>
<p>It comprises three spectral lines, where light is emitted or absorbed in a narrow frequency range. These are each generated at a different range of temperatures (in the millions of degrees), so their relative brightness tells us about the coronal temperature in different regions. </p>
<p>Mapping the corona’s temperature informs advanced, computer-based models of its behaviour. These models must include mechanisms for how the coronal plasma is heated to such high temperatures. Such mechanisms might include the conversion of magnetic waves to thermal plasma energy, for example. If we show that some regions are hotter than others, this can be replicated in models. </p>
<p>This year’s eclipse also occurs during a time of heightened solar activity, so we could observe a <a href="https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections">coronal mass ejection (CME)</a>. These are huge clouds of magnetised plasma that are ejected from the Sun’s atmosphere into space. They can affect infrastructure near Earth, causing problems for vital satellites. </p>
<p>Many aspects of CMEs are poorly understood, including their early evolution near the Sun. Spectral information on CMEs will allow us to gain information on their thermodynamics, and their velocity and expansion near the Sun.</p>
<p>Our eclipse instruments have recently been proposed for a space mission called <a href="https://www.surrey.ac.uk/research-projects/feasibility-study-moon-enabled-sun-occultation-mission-mesom">Moon-enabled solar occultation mission (Mesom)</a>. The plan is to orbit the Moon to gain more frequent and extended eclipse observations. It is being planned as a UK Space Agency mission involving several countries, but led by University College London, the University of Surrey and Aberystwyth University.</p>
<p>We will also have an advanced commercial 360-degree camera to collect video of the April 8 eclipse and the observing site. The video is valuable for public outreach events, where we highlight the work we do, and helps to generate public interest in our local star, the Sun.</p><img src="https://counter.theconversation.com/content/226558/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Huw Morgan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The eclipse will allow scientists to get rare measurements of the Sun’s atmosphere.Huw Morgan, Reader in Physical Sciences, Aberystwyth UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2252412024-03-26T17:25:44Z2024-03-26T17:25:44ZPhotographing the eclipse? You’ll join a long history of people seeking proof of experience<p>If you are <a href="https://www.cbc.ca/news/canada/hamilton/eclipse-day-planning-1.7147091">one of the millions planning to view</a> the total solar eclipse on April 8, there is a good chance that you will take pictures of your experience. </p>
<p>And, like many before you, afterwards you may find that those pictures don’t measure up to your expectations, experiences and memories of viewing the eclipse.</p>
<p>We offer some technical tips for eclipse photography, but we also consider why so many of us are drawn to photograph these kinds of collective moments of awe and wonder — as we think about the larger context of visual culture around solar eclipses throughout history.</p>
<h2>Technical, safety challenges</h2>
<p>Photographing a solar eclipse presents some <a href="https://www.youtube.com/watch?v=dClhdu0oyWM">technical and safety challenges</a>. There are some preparations you can undertake, including ensuring your camera (<a href="https://www.cbc.ca/news/canada/total-solar-eclipse-phone-photos-2024-1.7149062">even smartphone cameras!</a>) has a solar filter. It is also important to be familiar with your camera, to practice using it in different light conditions before the eclipse. </p>
<p>The changes in light qualities will be quick and drastic, so familiarity with aperture and shutter speed will be important on the big day. A tripod will help reduce blurring when a longer exposure is required. If there are clouds, it’s still important to be cautious and wear protective glasses and the ability to capture an image will depend on the extent of cloud cover. The viewing experience will be different, but sky will still darken, creating changes in the colour and the way light passes through the clouds. </p>
<p>There are also some more creative ways to think about capturing the experience, including <a href="https://www.asc-csa.gc.ca/eng/youth-educators/activities/fun-experiments/eclipse-projector.asp">making a pinhole projector</a>. </p>
<p>This simple device can be made from a cardboard box and allows for both safe viewing and some interesting images.</p>
<h2>First photographs of eclipses</h2>
<p>But if your photographs don’t conform to your expectations, you are in good company. In 1842 Italian physicist <a href="https://hyperallergic.com/392269/the-first-photographs-of-a-solar-eclipse/">Gian Alessandro Majocchi attempted to photograph</a> the total solar eclipse that took place that July. Surviving records indicate he only had partial success: His resulting daguerreotype images — an early <a href="https://www.loc.gov/collections/daguerreotypes/articles-and-essays/the-daguerreotype-medium/#">photography technique invented by Louis-Jacques-Mandé Daguerre in 1839, involving treating a silver-coated copper plate with light sensitive chemicals</a> — are lost.</p>
<p>Majocchi was able to capture a few photographs <a href="https://babel.hathitrust.org/cgi/pt?id=hvd.fl1241&view=1up&seq=265">before and after</a> the <a href="https://www.cbc.ca/news/science/total-solar-eclipse-where-how-1.7129716">moments of totality</a>.</p>
<h2>Reminder of wonder, togetherness</h2>
<p>Apart from technical aspects, a successful photograph of the eclipse serves as a lasting reminder of the sense of wonder and the feeling of being part of something larger than ourselves. </p>
<p>This is the kind of event that brings people together, and the shared experience continues long after the eclipse ends through photographs that serve as memory markers and tangible proof that you were there to witness the eclipse. And even though many of us might end up with similar photographs, there is something significant about so many people taking pictures of the same event.</p>
<p>For example, <a href="https://psycnet.apa.org/record/2016-27715-001">taking photographs of events can increase a person’s enjoyment of the experience</a>, as the research of marketing professor Kristin Diehl and colleagues has examined. </p>
<p>Photography allows us to preserve memories, share them with others and relive those moments in the future. What makes an image stand out among the millions shared daily on social media often comes down to a combination of factors: its visual impact, the story it tells and the emotional resonance it can hold for others viewing it. In other words, much of what we share is about the broader experience.</p>
<h2>Proof of experience, connection across time</h2>
<p>Photographs also have long fulfilled a deep-seated need for proof of experience. We were there. Whether a blurry cell phone image of the <em>Mona Lisa</em> or a snapshot of the eclipse, these images serve as tangible reminders of our experiences. They validate our memories, anchor the stories we tell and allow us to share these moments with others. </p>
<p>Looking at images of people taking in <a href="https://www.atlasobscura.com/articles/century-eclipse-watching-photos">an eclipse during other eras can also offer a shared sense of connection across time</a>. This is a phenomenon that is bigger than us and these images connect us to the experiences of previous generations. </p>
<p>Scientific photographs of an eclipse, like the ones <a href="https://siarchives.si.edu/collections/siris_arc_308088">Thomas Smillie</a> made for the Smithsonian in 1900, may have been heralded as <a href="https://siarchives.si.edu/blog/smillie-and-1900-eclipse">technological breakthroughs</a>. Yet <a href="https://www.atlasobscura.com/articles/century-eclipse-watching-photos">there is something especially compelling about photographs of people gathered together, stopping for a moment and looking skyward</a>.</p>
<h2>Photographs yield partial insights</h2>
<p>A <a href="https://hyperallergic.com/392269/the-first-photographs-of-a-solar-eclipse/">daguerreotype of a solar eclipse taken on July 28, 1851 is the first known successful photograph of the solar corona</a>. This image was made at the Royal Prussian Observatory in Königsberg (contemporary Kaliningrad, Russia) by Johann Julius Friedrich Berkowski with the aid of a telescope. <a href="https://www.space.com/37656-first-total-solar-eclipse-photo-ever.html">The 84-second exposure allowed Berkowski to capture the moment in incredible detail</a>.</p>
<p>In 1890, the <em>American Journal of Photography</em> proclaimed <a href="https://babel.hathitrust.org/cgi/pt?id=hvd.fl1241&view=1up&seq=265">“probably in no department of science, certainly in no branch of astronomical science, has photography been of such use as in the study of solar eclipses</a>.” As the editors note, photography certainly can shape our understanding of the world, help to create new knowledge and provide valuable insights into the nature of the universe. </p>
<p>But there is also a limit to what photography can do. The experience of a solar eclipse goes beyond the visible: <a href="https://eclipse2017.nasa.gov/temperature-change-during-totality">temperatures drop</a>, <a href="https://www.audubon.org/news/total-solar-eclipse-coming-how-will-birds-and-other-wildlife-react">the behaviour of nonhuman animals can suddenly shift</a> and many report <a href="https://www.cbc.ca/player/play/1.7149511">unanticipated emotional or spiritual responses</a>.</p>
<h2>Many visual, artistic responses</h2>
<p>Further, there is a long history of <a href="https://doi.org/10.1038/508314a">eclipses being recorded in a range of different visual media</a>. For example, the <a href="https://doi.org/10.1017/S1743921314004621">Shang Dynasty in China provides a visual record of solar eclipses</a> via ancient script carved <a href="https://asia-archive.si.edu/learn/chinas-calligraphic-arts/oracle-bone-script">into oracle bones</a>.</p>
<p><a href="https://smarthistory.org/peter-paul-rubens-elevation-of-the-cross/">A 1610 painting by Peter Paul Rubens, called <em>The Elevation of the Cross</em></a>, illustrates the long and complex history of connections between phenomenon like eclipses and religious beliefs. In the early 20th century, American painter Howard Russell Butler produced a series of paintings in which he focused on <a href="https://hyperallergic.com/393623/howard-russell-butler-eclipse-paintings/">aspects of the eclipse that were difficult to capture with black and white photography — the changing quality of light and colours of the sky</a>. </p>
<p>The <a href="https://artmuseum.princeton.edu/transient-effects/eclipses-art/blackstar">video accompanying David Bowie’s <em>Black Star</em></a> (2016) opens with a total solar eclipse.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/kszLwBaC4Sw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Video for David Bowie’s ‘Black Star.’</span></figcaption>
</figure>
<p>This is evocative visual imagery that complements the song’s themes of mortality — and offers a nod to long-held understandings of an eclipse as a symbol of impending doom. This symbolism was especially poignant as this was the title track of Bowie’s last studio album.</p>
<p>These types of artistic responses to celestial events foreground personal interpretation and emotional responses. They also foreground and reflect social, cultural, and spiritual meanings associated with a solar eclipse. </p>
<p>Could the act of sharing our eclipse photographs provide a point of fusion between providing evidence and these less tangible — but equally valid — moments of engagement?</p><img src="https://counter.theconversation.com/content/225241/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Keri Cronin has previously received funding from the Social Sciences and Humanities Research Council of Canada.</span></em></p><p class="fine-print"><em><span>Amy Friend does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Apart from technical aspects, a successful photograph of the eclipse serves as a lasting reminder of the sense of wonder and the feeling of being part of something larger than ourselves.Amy Friend, Associate professor, Visual Arts Department, Brock UniversityKeri Cronin, Professor, History of Art & Visual Culture, Brock UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2266432024-03-26T17:01:48Z2024-03-26T17:01:48ZThe ‘worm moon’ once marked the spring return of earthworms – until global warming kicked in<figure><img src="https://images.theconversation.com/files/584414/original/file-20240326-16-7psmz6.jpg?ixlib=rb-1.1.0&rect=8%2C8%2C5982%2C3970&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><span class="source">Darkfoxelixir / shutterstock</span></span></figcaption></figure><p>The worm moon has risen. The final full moon of winter in the northern hemisphere appeared on <a href="https://www.theguardian.com/news/gallery/2024/mar/25/a-volcanic-eruption-and-a-worm-moon-photos-of-the-day">March 25</a> and owes its name to <a href="https://www.nationalgeographic.co.uk/2019/02/full-moon-names-explained">Native Americans</a> who noted winter’s end by the trails of earthworms it illuminated on the newly thawed soil. </p>
<p>Common names of full moons generally come from seasonal animals, colours or crops: wolf moon, pink moon, harvest moon. But the worm moon may be losing its significance, as climate change leads to wetter summers and milder winters in much of the world. I’ve been an earthworm scientist for more than three decades, and, of late, I’m seeing signs of worms at the surface in months when they used to be inactive.</p>
<p>To track how the worm moon might be changing we can look at a particular earthworm species (<em>Lumbricus terrestris</em>, aka the dew worm, nightcrawler or lob worm) which is unusually easy to track. Also sometimes called the common earthworm, if you see a big worm in the garden, it’s likely to be this species. </p>
<hr>
<p><em>Do the seasons feel increasingly weird to you? You’re not alone. Climate change is distorting nature’s calendar, causing plants to flower early and animals to emerge at the wrong time.</em></p>
<p><em>This article is part of a series, <a href="https://theconversation.com/uk/topics/wild-seasons-152175?utm_source=InArticleTop&utm_medium=TCUK&utm_campaign=WS">Wild Seasons</a>, on how the seasons are changing – and what they may eventually look like.</em></p>
<hr>
<p>Most worms spend most of their lives underground, but the dew worm almost completely leaves its deep burrow, with tail tip left in, as it ventures on to the soil surface every night to feed on dead leaves. These worms also mate on the soil surface. They may be hermaphrodite (both male and female) but still need to exchange sperm with a partner – each fertilising the other.</p>
<p>Such activities usually take place under the cover of darkness to avoid birds and other potential daytime predators. However, the worms are restricted by soil conditions at the top of the burrow. They cannot surface if the soil is baked dry (in summer) or frozen (in winter). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large worm in soil" src="https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584428/original/file-20240326-22-f8tpaz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Lumbricus terrestris</em> is a large earthworm found across the world.</span>
<span class="attribution"><span class="source">D. Kucharski K. Kucharska / shutterstock</span></span>
</figcaption>
</figure>
<p>In theory, the passing of winter would kickstart the surface activity (and therefore the worm moon). Yet if the winter isn’t that cold, we perhaps need to reconsider which moon should be termed the “worm moon”. Maybe a date earlier in the year would be better, or perhaps the term may cease to have any real meaning.</p>
<p>We can get a sense of how these earthworms can adapt to changing circumstances by looking at the northernmost populations, such as those in Finland, which are exposed to 24 hours of daylight in summer. These “white nights”, when the sky never gets dark, put additional stress on these worms as they cannot use darkness to hide from predators but must still feed and mate at the surface while conditions allow.</p>
<h2>Finland v Lancashire v Ohio</h2>
<p>A decade ago, colleagues and I set out to see if Finnish worms behaved any differently during the white night period to worms of the same species taken to Finland from lower latitudes. We <a href="https://www.sciencedirect.com/science/article/pii/S0038071714000248">compared native dew worms</a> from an area in south-west Finland at 60°N, with those from Lancashire in the UK (53°N) and Ohio in the US (40°N, more than 2,000km south of Finland), both of which have dark nights throughout the year.</p>
<p>We put these worms outdoors under ambient (white night) light in soil-filled drainpipes (1m deep) in a large, controlled temperature water bath (an old chest freezer with no lid). We looked at their feeding and mating, and, in parallel, repeated the experiment under darkened conditions at “night”. </p>
<p>In darkness, worms from all three origins were similarly very active in feeding and mating. </p>
<p>Under ambient conditions, the Finnish worms were generally the most active. They emerged earlier in the evening and ceased their activity later in the morning than those from the two more southerly populations. It seems the species had adapted to its conditions, with a normal reluctance to surface during daylight overtaken by a need to feed and mate.</p>
<p>Perhaps with warming soils, earthworms are becoming more active during traditionally colder or drier months. This will increase their effect on the soil – earthworms are ecosystem engineers and generally lead to increased soil fertility – which is generally positive, even if churning up the soil can lead to <a href="https://www.nature.com/articles/nclimate1692">further decomposition and greenhouse gas emissions</a>. </p>
<p>A worm moon and white nights would never normally appear in the same sentence. However, changes in the activities of worms as the global climate becomes less predictable means we may need to rethink at least one of our terms of reference that has marked time for hundreds or thousands of years. Enjoy the traditional worm moon while it lasts.</p><img src="https://counter.theconversation.com/content/226643/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Richard Butt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The last full moon of winter can illuminate earthworms in newly-thawed soil.Kevin Richard Butt, Reader in Ecology, University of Central LancashireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2242982024-03-26T12:48:20Z2024-03-26T12:48:20Z3 ways to use the solar eclipse to brighten your child’s knowledge of science<figure><img src="https://images.theconversation.com/files/583531/original/file-20240321-16-fk38cj.jpg?ixlib=rb-1.1.0&rect=0%2C60%2C6720%2C4406&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In no case should a child look directly at the solar eclipse, but there are special eclipse glasses.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/child-observes-the-annular-solar-eclipse-by-using-special-news-photo/1724609614?adppopup=true">Anadolu via Getty Images</a></span></figcaption></figure><p>When the Moon passes between the Sun and the Earth on April 8, 2024, it will represent a rare astronomical event that won’t take place for <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/">another 20 years</a> – a <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/where-when/">total solar eclipse</a>. For parents and educators, at least those who live along an arc of land from Texas up through Indiana and Maine, it offers a unique and memorable learning opportunity. </p>
<p>As STEM researchers at <a href="https://hhs.purdue.edu/center-for-early-learning/">Purdue’s Center for Early Learning</a>, we suggest three ways to make the total solar eclipse a fun experience for young children and <a href="https://doi.org/10.1080/15248372.2019.1620232">teach some important science</a> along the way.</p>
<h2>1. Discuss historical versus modern understandings of eclipses</h2>
<p>It is important that children learn to <a href="https://www.sciencepracticesleadership.com/uploads/1/6/8/7/1687518/reiser,_berland,_&_kenyon_(2012).pdf">consider and contrast multiple ideas</a> when developing explanations for why something happens. One way to do this is to compare historical and modern explanations for why solar eclipses occur. </p>
<p>Share with the kids that, historically, many people across cultures feared eclipses. Some thought they <a href="https://www.britannica.com/list/the-sun-was-eaten-6-ways-cultures-have-explained-eclipses">signified disapproval from the gods</a>. Others believed they predicted bad tidings to come, including <a href="https://www.folger.edu/blogs/collation/black-monday-great-solar-eclipse-1652/">shipwrecks and storms</a>.</p>
<p>Contrast those explanations with easy-to-understand scientific explanations of today. Britannica Kids offers a great <a href="https://kids.britannica.com/kids/article/eclipse/353079">resource for children under 8</a>. Scientific American has a webpage that <a href="https://www.scientificamerican.com/article/how-to-explain-aprils-total-solar-eclipse-to-kids/">works well for older kids</a>. </p>
<p>When contrasting scientific evidence with historical beliefs, it is important not to be critical of other cultures. Use the eclipse to talk about how scientific knowledge is built over time through observation. There are many things we do not know now that we will learn 10, 20 or even 100 years from now. </p>
<h2>2. Have conversations using scientific language</h2>
<p>Teaching children about the solar eclipse isn’t just about explaining the what and the why. It’s also about engaging in rich dialogue. Our prior research shows that young children’s science knowledge is <a href="https://doi.org/10.1016/j.cogdev.2020.100981">highly based on language</a>. Both <a href="https://doi.org/10.1016/j.jecp.2022.105473">parents</a> and <a href="https://doi.org/10.1080/10409289.2010.507496">teachers</a> play a role in shaping this language. </p>
<p>Use science-related vocabulary to enrich children’s understanding of the eclipse. Examples include: orbit, rotate, spin, reemerge, Sun, Moon, Earth, far, distance, total and partial. </p>
<p><a href="https://doi.org/10.1080/07370008.2011.608027">Children understand science concepts more deeply</a> and <a href="https://doi.org/10.1002/trtr.2075">use more complex vocabulary</a> when adults use inquiry-based strategies. For example, adults can ask children what they see happening while watching the eclipse and why they think that is. Then the adults can ask the children to make predictions about what else could happen and provide evidence for their explanations. </p>
<p>Children can document their observations throughout the eclipse in their own <a href="https://doi.org/10.1016/j.ecresq.2004.01.009">science journals</a> using both science-related vocabulary and drawings of what they see. The journals are a great opportunity to discuss their ideas and have rich conversations.</p>
<h2>3. Use household items to help children understand the eclipse</h2>
<p>Three-dimensional models allow children to visualize things that are otherwise difficult to see, such as the orbit of the Earth and the Moon. Comparisons between the model and their observations of real life, especially when guided by a teacher or parent, <a href="https://doi.org/10.1177/0956797619864601">help children build knowledge</a> about complex topics in science.</p>
<p>During the solar eclipse, the Moon moves directly between the Earth and the Sun. In small groups at school or at home, one child can represent the Earth, while another holds a basketball to represent the Sun and another a tennis ball to represent the Moon.</p>
<p>The child representing the Earth can orbit the Sun and rotate in place, experimenting with changing their distance from the Sun and Moon. Closing one eye, the child may eventually see the basketball completely blocked by the tennis ball when it aligns just right. This is what happens in a total solar eclipse. </p>
<p>In this exercise, children are not only modeling the eclipse but also building scientific vocabulary. Throughout the activity, parents and teachers can ask children to compare and contrast the model to their own observations. They can ask questions, such as why do the Sun and Moon look like they are similar sizes in the sky, even though we know that the Sun is many times larger than the Moon? If the Moon is smaller, how does it block the Sun completely? The key is to help children generate hypotheses, test their ideas and then develop new conclusions.</p>
<p>We hope these ideas will encourage everyone to take advantage of this wonderful scientific learning experience. We also warn you not to look directly into the Sun during the eclipse and to get the right <a href="https://eclipse.aas.org/eye-safety/viewers-filters">eclipse glasses</a>. Looking directly at the Sun, even through sunglasses or cameras, <a href="https://theconversation.com/total-solar-eclipses-while-stunning-can-damage-your-eyes-if-viewed-without-the-right-protection-221381">can cause severe injury to the eyes</a>.</p><img src="https://counter.theconversation.com/content/224298/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>If you have young kids, the solar eclipse on April 8, 2024, represents a rare opportunity to teach them about science.David J. Purpura, Professor of Human Development and Family Science; Director of the Center for Early Learning, Purdue UniversityLauren Westerberg, Doctoral Candidate in Human Development and Family Science, Purdue UniversitySona Kumar, Postdoctoral Researcher in the Department of Human Development and Family Science, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2259552024-03-22T12:32:20Z2024-03-22T12:32:20ZAn eclipse for everyone – how visually impaired students can ‘get a feel for’ eclipses<figure><img src="https://images.theconversation.com/files/583493/original/file-20240321-24-k7j1j4.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C1997%2C1398&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A solar eclipse approaching totality. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/Total%20Solar%20Eclipse%20Photo%20Gallery/d4f2edfa2e47448980ce303f299063ae?hpSectionId=8053d9e3a7de4b25a8bccd33428f5964&st=hpsection&mediaType=photo&sortBy=arrivaldatetime:desc&dateRange=Anytime&totalCount=3429&currentItemNo=22">AP Photo/Richard Vogel, File</a></span></figcaption></figure><p>Many people in the U.S. will have an opportunity to witness nearly four minutes of a <a href="https://theconversation.com/what-would-a-solar-eclipse-look-like-from-the-moon-an-astronomer-answers-that-and-other-total-eclipse-questions-81308">total solar eclipse</a> on Monday, April 8, 2024, as it moves from southern Texas to Maine. But in the U.S., over 7 million people are <a href="https://nfb.org/blindness-statistics">blind or visually impaired</a> and may not be able to experience an eclipse the traditional way. </p>
<p>Of course they, like those with sight, will feel colder as the Sun’s light is shaded, and will hear the songs and sounds of birds and insects change as the light dims and brightens. But much of an eclipse is visual.</p>
<p>We are a <a href="https://scnasaepscor.charleston.edu/contact-us/">planetary scientist</a> and <a href="https://www.edinboro.edu/academics/schools-and-departments/cshp/departments/geosciences/planetarium/director.php">an astronomer</a> who, with funding and support from NASA’s <a href="https://sservi.nasa.gov/articles/">Solar System Exploration Research Virtual Institute</a>, have created and published a set of <a href="https://sservi.nasa.gov/books/eclipses.html">tactile graphics</a>, or graphics with raised and textured elements, on the 2024 total solar eclipse. </p>
<p>The guide, called “Getting a Feel for Eclipses,” illustrates the paths of the 2017 total, 2023 annular and <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/where-when/">2024 total solar eclipses</a>. In a <a href="https://theconversation.com/what-would-a-solar-eclipse-look-like-from-the-moon-an-astronomer-answers-that-and-other-total-eclipse-questions-81308">total eclipse</a>, the Moon fully blocks the Sun from Earth view, while during an <a href="https://www.nesdis.noaa.gov/annular-solar-eclipse">annular eclipse</a>, a narrow ring of sunlight can be seen encircling the Moon. </p>
<p>The tactile graphics and associated online content detail the <a href="https://theconversation.com/solar-eclipses-result-from-a-fantastic-celestial-coincidence-of-scale-and-distance-224113">specific alignment of the Earth, Moon and Sun</a> under which eclipses occur. </p>
<p>To date, we have distributed almost 11,000 copies of this book to schools for the blind, state and local libraries, the Library of Congress and more.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&rect=25%2C3%2C2085%2C1553&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the US with three curved lines stretching across, indicating the eclipses of 2024, 2023 and 2017." src="https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&rect=25%2C3%2C2085%2C1553&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=556&fit=crop&dpr=1 754w, https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=556&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/583257/original/file-20240320-20-10b7nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=556&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">‘The Getting A Feel for Eclipses’ guide helps blind and visually impaired people learn about the eclipse.</span>
<span class="attribution"><a class="source" href="https://sservi.nasa.gov/books/eclipses.html">NASA SSERVI</a></span>
</figcaption>
</figure>
<h2>Why publish a tactile book on eclipses?</h2>
<p>NASA has <a href="https://science.nasa.gov/eclipses">lots of explanatory material</a> that helps people visualize and understand rare phenomena like eclipses. But for people with visual impairments, maps and images don’t help. For tactile readers, their sense of touch is their vision. That’s where this guide and our other tactile books come in.</p>
<p>Over <a href="https://nfb.org/blindness-statistics">65,000 students in the U.S.</a> are blind or visually impaired. After working with several of our students who are totally blind, we wanted to find out how to make events like eclipses as powerful for these students as they are for us. We also wanted to help our students visualize and understand the concept of an eclipse. </p>
<p>These aims resulted in the three <a href="https://www.pathstoliteracy.org/tactile-graphics/">tactile graphics</a>, which are physical sheets with textures and raised surfaces that can be interpreted through touch, <a href="https://sservi.nasa.gov/books/eclipses.html">as well as online content</a>. </p>
<p>The first tactile graphic models the <a href="https://theconversation.com/solar-eclipses-result-from-a-fantastic-celestial-coincidence-of-scale-and-distance-224113">alignment of the Earth, Moon and Sun</a>. The second illustrates the phases of an eclipse as the Moon moves in between the Earth and Sun to full totality, and then out of the way. The third includes a map of the continental U.S. that illustrates the paths of three eclipses: the <a href="https://www.weather.gov/pah/TotalSolarEclipse2017">Aug. 21, 2017, total eclipse</a>, the <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2023/where-when/">Oct. 14, 2023, annular eclipse</a> and the <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/where-when/">Apr. 8, 2024, total eclipse</a>. We used different textures to illustrate these concepts.</p>
<p>Each book includes a QR code on the front cover, outlined by a raised square boundary. The code links to <a href="https://sservi.nasa.gov/books/eclipses.html">an online guide</a> that leads the user through the content behind the graphics while also providing background information. With the online content, users may opt to print the information in large font or have it read to them by a device.</p>
<p>Although initially created to assist visually impaired audiences, these books are still helpful resources for those with sight. Some students can see but might learn better when able to explore the tactile parts of the guide while listening to the audio. Often it’s helpful for students to get the same information presented in different styles, with options to read or have the content information read to them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sheet of paper with raised textures labeled Sun, Umbra, Moon and Totality, with three students touching the textures." src="https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/583490/original/file-20240321-18-camylh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Students at Florida School for the Deaf and Blind in St. Augustine explore tactiles 1 and 2.</span>
<span class="attribution"><span class="source">Florida School for the Deaf and Blind</span></span>
</figcaption>
</figure>
<h2>How are the books made?</h2>
<p>We hand-make each book starting by identifying which science concepts the user will likely want to know, and which illustrations can support those concepts.</p>
<p>Once identified, the next step is to create a tactile master, or model, which has one or more raised textures that help to define the science concepts. We pick a set of unique textures to use on the master to signify different items, so the Sun feels different than the Earth. This way, the textures of the graphics become part of the story being shared. </p>
<p>For example, in a model of the Sun’s surface, we use <a href="https://www.britannica.com/plant/Spanish-moss">Spanish moss</a> to create the dynamic texture of the Sun. In past projects, we’ve used textures like doll hair, sand and differently textured cardboard to illustrate planet features, instruments on spacecraft, fine surface features and more. Then, we add <a href="https://www.afb.org/blindness-and-low-vision/braille/what-braille">Braille labels</a> for figure titles, key features and specific notes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A circle filled with moss." src="https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/583492/original/file-20240321-28-ku4w3n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The tactile master – Spanish moss – used for the Sun.</span>
<span class="attribution"><span class="source">Cassandra Runyon</span></span>
</figcaption>
</figure>
<p>Once we’ve finished making the masters and laying out each page, a small family print shop – McCarty Printing in Erie, Pennsylvania – prints the page titles and key feature labels on Brailon, a type of plastic paper. </p>
<p>Once printed, we place the masters and the Brailon sheets on a thermoform Machine, which heats up the sheets and creates a vacuum that forms the final tactile graphics. Then, we return the pages to McCarty Printing for binding. </p>
<h2>Viewing and experiencing the eclipse</h2>
<p>Like fully sighted people, people with partial vision should avoid looking directly at the Sun. Instead, everyone should <a href="https://theconversation.com/total-solar-eclipses-while-stunning-can-damage-your-eyes-if-viewed-without-the-right-protection-221381">use eclipse glasses</a>. If you don’t have eclipse glasses, you can use an indirect viewing method such as a <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/safety/">colander or pinhole projector</a>.</p>
<p>As the eclipse approaches totality, take time to enjoy your surroundings, feel the changes in temperature and light, and note how the animals around you react to the remarkable event using another of your senses – sound.</p><img src="https://counter.theconversation.com/content/225955/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cassandra Runyon receives funding from NASA's Office of STEM Engagment through the National Space Grant Program and the Established Program to Stimulate Competitive Research (EPSCoR) as well as NASA's Solar System Exploration Research Virtual Institure (SSERVI). She is the Director of both the NASA South Carolina Space Grant Consortium and NASA South Carolina EPSCoR program and Vice Chair of the National Council of Space Grant Directors.</span></em></p><p class="fine-print"><em><span>David Hurd receives funding from the NSF and NASA SSERVI.</span></em></p>Eclipses are rare, fantastic celestial events. Here’s how educators can help visually impaired students enjoy eclipses alongside their sighted peers.Cassandra Runyon, Professor of Geology & Environmental Geosciences, College of CharlestonDavid Hurd, Professor of Geosciences, Pennsylvania Western UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2227072024-03-13T19:13:22Z2024-03-13T19:13:22ZTotal solar eclipses provide an opportunity to engage with science, culture and history<figure><img src="https://images.theconversation.com/files/580943/original/file-20240311-16-li8vda.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3724%2C2146&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Throughout time, eclipses have inspired societies to understand the cosmos and its events.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>On April 8, 2024, there will be a total solar eclipse in Canada. This is an opportunity to experience, learn from and participate in the excitement and wonder. And rather than hiding inside, researchers have been communicating how people can safely enjoy this unique opportunity.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/on-april-8-2024-parts-of-ontario-quebec-the-maritimes-and-newfoundland-will-see-a-total-eclipse-of-the-sun-heres-how-to-get-ready-for-it-203382">On April 8, 2024, parts of Ontario, Québec, the Maritimes and Newfoundland will see a total eclipse of the sun. Here's how to get ready for it.</a>
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<p>Roughly every 18 months, the sun, moon and Earth come into perfect alignment and somewhere on Earth <a href="https://eclipse.gsfc.nasa.gov/SEatlas/SEatlas.html">experiences a solar eclipse</a>. During this phenomenon, the moon casts a roughly 250 km wide shadow onto Earth.</p>
<p>This ephemeral daytime darkness can be a once-in-a-lifetime experience. The last time Toronto experienced a total solar eclipse was on <a href="http://xjubier.free.fr/en/site_pages/solar_eclipses/xSE_GoogleMap3.php?Ecl=+19250124&Acc=2&Umb=1&Lmt=1&Mag=0&Lat=43.69660&Lng=-79.41391&Elv=162.0&Zoom=8&LC=1">Jan. 24, 1925</a>; the next total solar eclipse will occur in 120 years, on <a href="http://xjubier.free.fr/en/site_pages/solar_eclipses/xSE_GoogleMap3.php?Ecl=+21441026&Acc=2&Umb=1&Lmt=1&Mag=0&Lat=43.69629&Lng=-79.29982&Elv=127.0&Zoom=8&LC=1">Oct. 26, 2144</a>.</p>
<p>Our interpretation of, and response to, total solar eclipses has advanced enormously. Eclipses were once considered cosmic omens that predicted dying kings, good harvests or the need for new territorial treaties. Today, they provide a unique opportunity to consider the physical nature of the universe, and the cosmic privilege of witnessing the alignment of the moon and sun. </p>
<h2>Eclipses and knowledge creation</h2>
<p>Due to their sudden darkness, solar eclipses have been perceived <a href="https://www.cnn.com/2017/07/25/us/history-solar-eclipse/index.html">through history as catastrophic events</a>. Many societies developed stories to <a href="https://www.britannica.com/list/the-sun-was-eaten-6-ways-cultures-have-explained-eclipses">explain these unusual events</a>, often filled with fear and violence. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="an illustration of a golden brown demon eating a yellow disc against a purple background" src="https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=567&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=567&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580949/original/file-20240311-26-98odlu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=567&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A mural of the Hindu demon Rahu swallowing the moon at the temple Wat Phang La in southern Thailand.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/anandajoti/10684670235/">(Anandajoti Bhikkhu/flickr)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Indian myths tell of an <a href="https://www.washingtonpost.com/graphics/2017/lifestyle/eclipse-myths/">immortal demon seeking revenge on Vishnu by trying to eat the sun and moon</a>. The Pomo, Indigenous people of Northern California, describe <a href="https://www.exploratorium.edu/eclipse/eclipse-stories-from-around-the-world">a huge angry bear trying to eat the sun</a>. In other mythologies, eclipses were thought to be heavenly forces removing our source of warmth and life.</p>
<p>Beliefs about eclipses motivated ancient Greek astronomers to create the <a href="https://doi.org/10.1371/journal.pone.0103275">antikythera mechanism</a>, a complex analog computer that predicted the timing of future eclipses with a precision of 30 minutes. These predictions were critical for Greek society as a solar eclipse could mean an upcoming death of the king, requiring the appointment of a pseudo-emperor to be killed instead.</p>
<p>Our reactions to eclipses have evolved, driving us to better understand the solar system and the universe at large. </p>
<p>During the eclipse on Aug. 18, 1868, astronomers Norman Lockyer and Pierre Janssen each studied the light from the solar corona to <a href="https://doi.org/10.1007/978-1-4614-5363-5">discover a new chemical element</a>. This chemical element was named helium, after the Greek word for the sun. </p>
<p>On May 29, 1919, Frank Watson Dyson and Arthur Stanley Eddington studied the <a href="https://doi.org/10.1098/rsta.1920.0009">bent path of starlight</a> during a total solar eclipse for the first experimental “<a href="https://timesmachine.nytimes.com/timesmachine/1919/11/10/118180487.pdf">triumph of Einstein’s theory</a>” of general relativity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="ancient greenish square fragments" src="https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580945/original/file-20240311-20-25sylo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fragments of an antikythera mechanism on display at a museum in Athens, Greece.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Eclipse experiences</h2>
<p>Unlike many other cosmic events, such as meteor showers or comets, which require expensive telescopes or <a href="https://darksky.org/what-we-do/international-dark-sky-places/">dark sky places</a>, eclipses are a barrier-free celestial event. To safely enjoy the eclipse, one simply needs eclipse viewing glasses or <a href="https://www.jpl.nasa.gov/edu/learn/project/how-to-make-a-pinhole-camera/">a cardboard box</a>. </p>
<p>Many universities across Canada are using the opportunity of the total solar eclipse to engage with people to safely experience this astronomical phenomenon. For example, Queen’s University in Kingston, Canada is making <a href="https://www.queensu.ca/physics/2024-total-solar-eclipse/eclipse-glasses">120,000 eclipse glasses available</a> to make safe eclipse viewing possible for anyone.</p>
<p>In the spirit of education, hundreds of <a href="https://astrosociety.org/education-outreach/amateur-astronomers/eclipse-ambassadors/program.html">eclipse ambassadors</a> are heading to schools to engage with students about having a profound and safe experience during the eclipse. These ambassadors lead workshops on building inexpensive pinhole cameras to project the sun during the eclipse, explaining unique features that can be seen during eclipses, such as <a href="https://science.nasa.gov/resource/baileys-beads/">Bailey’s beads</a> and the <a href="https://www.nasa.gov/image-article/diamond-ring-effect/">diamond ring effect</a>, and helping everyone appreciate the vastness of the solar system.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a black circle surrounded with a ring of light that is thicker in the lower righthand quadrant" src="https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580952/original/file-20240311-20-8t2snr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Baily’s Beads effect occurs when gaps in the moon’s rugged terrain allow sunlight to pass through in some places just before the total phase of the eclipse.</span>
<span class="attribution"><a class="source" href="https://science.nasa.gov/resource/baileys-beads/">(Aubrey Gemignani/NASA)</a></span>
</figcaption>
</figure>
<p>These efforts demonstrate the universal value of science, and promote science engagement beyond classrooms and institutions.</p>
<p>Not only is the upcoming eclipse being leveraged as an opportunity to inspire the next generation of scientists, but it is also being used for the advancement of scientific knowledge. Unlike the experiments of Dyson, Eddington and Lockyer that were limited to the academy, today’s institutions are mobilizing the public to conduct citizen science experiments. </p>
<p>Initiated by NASA, the <a href="https://eclipsemegamovie.org/goals">Eclipse Megamovie project</a> will use photos taken during totality of the solar eclipse to study the solar corona. In 2017, photos collected during the total eclipse helped researchers identify a plasma plume in the solar corona. The 2024 eclipse will help researchers study this plume in greater detail. </p>
<p>Anyone with a DSLR camera and a tripod can submit a picture of the total solar eclipse to the Eclipse Megamovie project. The public data collected for the 2024 eclipse will far exceed what could be accomplished by any one experiment or location.</p>
<p>April’s total solar eclipse, and others to come, will remind people that science is exciting and inspiring, and that scientific expertise is of profound universal value. Such a celestial coincidence is an opportunity to engage with local communities and discuss the origin and mechanics of our solar system, all while including the public in scientific discovery through crowd-sourcing images of their experience. </p>
<p>All that’s left is to hope for clear skies and marvel once more at the cosmos.</p><img src="https://counter.theconversation.com/content/222707/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nikhil Arora receives funding from the National Sciences and Engineering Research Council of Canada.</span></em></p><p class="fine-print"><em><span>Mark Richardson is based at the Arthur B. McDonald Canadian Astroparticle Physics Research Institute, who has received funding from the Canada First Research Excellence Fund. </span></em></p>Eclipses have inspired myths, predictions and scientific discoveries. The total solar eclipse occurring on April 8 provides a once-in-a-lifetime opportunity to engage with science and the cosmos.Nikhil Arora, Postdoctoral fellow, Physics, Engineering Physics & Astronomy, Queen's University, OntarioMark Richardson, Manager for Education and Public Outreach, Adjunct Professor of Physics and Astronomy, Queen's University, OntarioLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2241132024-03-12T18:55:13Z2024-03-12T18:55:13ZSolar eclipses result from a fantastic celestial coincidence of scale and distance<figure><img src="https://images.theconversation.com/files/580531/original/file-20240307-28-al4bnq.jpg?ixlib=rb-1.1.0&rect=23%2C15%2C5247%2C3690&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar eclipses happen because of a few factors, including the Moon's size and distance from the Sun. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/EclipseKentucky/8b202fc6981149ebb1c59158d49e348d/photo?Query=eclipse&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=478&digitizationType=Digitized&currentItemNo=7&vs=true&vs=true">AP Photo/Timothy D. Easley</a></span></figcaption></figure><p>On April 8, 2024, millions across the U.S. will have the once-in-a-lifetime chance to view a total solar eclipse. <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/where-when/">Cities including</a> Austin, Texas; Buffalo, New York; and Cleveland, Ohio, will have a direct view of this rare cosmic event that lasts for just a few hours.</p>
<p>While <a href="https://theconversation.com/astro-tourism-chasing-eclipses-meteor-showers-and-elusive-dark-skies-from-earth-207969">you can see many astronomical events</a>, such as <a href="https://theconversation.com/comets-101-everything-you-need-to-know-about-the-snow-cones-of-space-213342">comets</a> and meteor showers, from anywhere on Earth, eclipses are different. You need to travel to what’s called the <a href="https://theconversation.com/when-the-sun-goes-dark-5-questions-answered-about-the-solar-eclipse-81308">path of totality</a> to experience the full eclipse. Only certain places get an eclipse’s full show, and that’s because of scale. </p>
<p>The relatively small <a href="https://www.space.com/18135-how-big-is-the-moon.html">size of the Moon</a> and its shadow make eclipses truly once-in-a-lifetime opportunities. On average, total solar eclipses are visible somewhere on Earth once every few years. But from any one location on Earth, <a href="https://eclipse.gsfc.nasa.gov/SEcirc/SEcirc.html">it is roughly 375 years</a> between solar eclipses.</p>
<p><a href="https://science.psu.edu/astro/people/cxp137">I’m an astronomer</a>, but I have never seen a total solar eclipse, so I plan to drive to Erie, Pennsylvania, in the path of totality, for this one. This is one of the <a href="https://eclipse.gsfc.nasa.gov/SEmap/SEmapNA/TSENorAm2051.gif">few chances I have</a> to see a total eclipse without making a much more expensive <a href="https://theconversation.com/astro-tourism-chasing-eclipses-meteor-showers-and-elusive-dark-skies-from-earth-207969">trip to someplace more remote</a>. Many people have asked me why nearby eclipses are so rare, and the answer is related to the size of the Moon and its distance from the Sun.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/fmtGqOxxmEU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Those in the path of totality will have the opportunity to see a total solar eclipse this April.</span></figcaption>
</figure>
<h2>Size and scale</h2>
<p>You can observe a solar eclipse when the Moon passes in front of the Sun, blocking some or all of the Sun from view. For people on Earth to be able to see an eclipse, the Moon, while orbiting around the Earth, must lie exactly along the observer’s line of sight with the Sun. Only some observers will see an eclipse, though, because not everyone’s view of the Sun will be blocked by the Moon on the day of an eclipse. </p>
<p>The fact that solar eclipses happen at all is a bit of a numerical coincidence. It just so happens <a href="https://science.nasa.gov/sun/facts/#hds-sidebar-nav-3">that the Sun</a> is approximately 400 times <a href="https://science.nasa.gov/moon/facts/#hds-sidebar-nav-3">larger than the Moon</a> and also 400 times more distant from the Earth. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo showing the Earth next to the Moon. The Earth is much larger." src="https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/581049/original/file-20240311-22-9ovtoi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earth’s size compared with the Moon. Distances not to scale.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/the-earth-and-moon-to-scale-royalty-free-image/136247709?phrase=earth+moon+size+comparison&adppopup=true">Laara Cerman/Leigh Righton/Stockbyte via Getty Images</a></span>
</figcaption>
</figure>
<p>So, even though the Moon is much smaller <a href="https://science.nasa.gov/sun/facts/">than the Sun</a>, it is just close enough to Earth to appear the same size as the Sun when seen from Earth. </p>
<p>For example, your pinky finger is much, much smaller than the Sun, but if you hold it up at arm’s length, it appears to your eye to be large enough to block out the Sun. The Moon can do the same thing – it can block out the Sun if it’s lined up perfectly with the Sun from your point of view. </p>
<h2>Path of totality</h2>
<p>When the Earth, Moon and Sun line up perfectly, the Moon <a href="https://science.nasa.gov/solar-system/skywatching/eclipses/solar-eclipses/2024-solar-eclipse/total-solar-eclipse-2024-the-moons-moment-in-the-sun/">casts a shadow onto the Earth</a>. Since the Moon is round, its shadow is round as it lands on Earth. The only people who see the eclipse are those in the area on Earth where the shadow lands at a given moment. </p>
<p>The Moon is continuously orbiting around the Earth, so as time goes on during the eclipse, the Moon’s shadow moves over the face of the Earth. Its shadow ends up looking like a thick line that can cover hundreds of miles in length. Astronomers call that line the <a href="https://science.nasa.gov/solar-system/skywatching/eclipses/new-nasa-map-details-2023-and-2024-solar-eclipses-in-the-us/">path of totality</a>. </p>
<p>From any given location along the path of totality, an observer can see the Sun completely eclipsed for a few minutes. Then, the shadow moves away from that location and the Sun slowly becomes more and more visible. </p>
<h2>A tilted orbit</h2>
<p>Solar eclipses don’t happen every single time the Moon passes in between Earth and the Sun. If that were the case, there would be a solar eclipse every month. </p>
<p>If you could float above the Earth’s North Pole and see the Moon’s orbit from above, you would see the Moon line up with the Sun once every time it orbits around the Earth, which is approximately once per month. From this high point of view, it looks like the Moon’s shadow should land on Earth every orbit. </p>
<p>However, if you could shift your perspective to look at the Moon’s orbit from the orbital plane, you would see that the Moon’s orbit is <a href="https://moon.nasa.gov/moon-in-motion/phases-eclipses-supermoons/overview/">tilted by about 5 degrees</a> compared with Earth’s orbit around the Sun. This tilt means that sometimes the Moon is too high and its shadow passes above the Earth, and sometimes the Moon is too low and its shadow passes below the Earth. An eclipse happens only <a href="https://svs.gsfc.nasa.gov/4324/">when the Moon is positioned just right</a> and its shadow lands on the Earth. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/JplGhSC-eGM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">There isn’t an eclipse every time the Moon passes in front of the Sun because of the Moon’s tilted orbit around Earth.</span></figcaption>
</figure>
<p>As time goes on, the Earth and the Moon continue spinning, and <a href="https://www.youtube.com/watch?v=JplGhSC-eGM">eventually the Moon aligns with Earth’s orbit</a> around the Sun at the same moment the Moon passes between the Sun and the Earth. </p>
<p>While only certain cities are in the path of totality for this April’s eclipse, the entire U.S. is still close enough to this path that observers outside of the path of totality will see a <a href="https://nso.edu/for-public/eclipse-map-2024">partial eclipse</a>. In those locations, the Moon will appear to pass in front of part of the Sun, leaving a crescent shape of the Sun still visible at the moment of maximum eclipse.</p><img src="https://counter.theconversation.com/content/224113/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Palma does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Many people will see a dazzling eclipse this April, but these events are possible only because of the sizes and precise distances between Earth, the Moon and the Sun.Christopher Palma, Teaching Professor, Department of Astronomy & Astrophysics, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2213812024-03-12T17:44:46Z2024-03-12T17:44:46ZTotal solar eclipses, while stunning, can damage your eyes if viewed without the right protection<figure><img src="https://images.theconversation.com/files/580528/original/file-20240307-30-bxdz7t.jpg?ixlib=rb-1.1.0&rect=47%2C6%2C4468%2C2383&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar eclipses don't come around often, but make sure to view these rare events with eclipse glasses to protect your vision. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/USEclipseSchools/0f2e25e7620440c0be042b6516d1acde/photo?Query=eclipse%20viewing&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=524&digitizationType=Digitized&currentItemNo=18&vs=true&vs=true">AP Photo/Charlie Riedel</a></span></figcaption></figure><p>On April 8, 2024, and for the second time in the past decade, people in the U.S. will have an opportunity to <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/">view a total solar eclipse</a>. But to do so safely, you’ll need to <a href="https://preventblindness.org/get-ready-for-the-next-eclipse/">wear proper protection</a>, or risk eye damage.</p>
<p>Earth is the only planet in our solar system where <a href="https://theconversation.com/when-the-sun-goes-dark-5-questions-answered-about-the-solar-eclipse-81308">solar eclipses can occur</a>. During these celestial events, the Moon passes between our planet and the Sun, blocking the Sun and casting a shadow over the Earth. Total eclipses rarely happen multiple times in the same region of a country during one’s lifetime. </p>
<p>The path of totality for <a href="https://science.nasa.gov/eclipses/">this spring’s eclipse</a>, where you can view the total eclipse, will extend over a 100-mile path that crosses through Mexico, Texas, New England and eastern Canada.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/fmtGqOxxmEU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Those in the path of totality will have the opportunity to see a total solar eclipse this April.</span></figcaption>
</figure>
<p>As excitement for the celestial show grows across the country, <a href="https://www.forbes.com/sites/jamiecartereurope/2024/03/09/11-ways-to-find-your-last-minute-hotel-for-the-total-solar-eclipse---but-be-quick/?sh=415b5585f4e2">hotels in the path of totality</a> have been booked up by eclipse enthusiasts. Museums and schools have <a href="https://solarsystem.nasa.gov/embeddable-eclipse-events/">planned viewing events</a>, and researchers have developed technology for the <a href="https://astrolab.fas.harvard.edu/LightSound.html">visually impaired and those with hearing loss</a> so more people have the opportunity to experience the eclipse.</p>
<p>Seeing an eclipse is a rare and special opportunity, but <a href="https://directory.hsc.wvu.edu/Profile/28506">as an ophthalmologist</a>, I know that looking directly at the Sun, even for a few moments, can severely damage your eyes. With a few easy precautions, eclipse viewers can protect themselves from severe and irreparable eye damage and vision loss.</p>
<h2>Safe eclipse viewing</h2>
<p>This year’s eclipse will unfold over a 75-minute period, from the moment the Moon starts to partially block the Sun until it completely moves away from it again. </p>
<p>During the partial eclipse period, when the Moon is partly blocking the Sun, you should never look directly at the Sun nor through binoculars, <a href="https://www.masterclass.com/articles/how-to-photograph-a-solar-eclipse">cameras</a> or <a href="https://www.space.com/how-to-photograph-a-solar-eclipse-with-a-smartphone">cellphones</a>. Sunglasses, photographic filters, exposed color film and welding glasses will dim the sunlight, but these items do not prevent <a href="https://www.aao.org/eye-health/tips-prevention/solar-eclipse-eye-safety">eye damage from the Sun’s very intense light rays</a>. </p>
<p>Only <a href="https://preventblindness.org/solar-eclipse-glasses/">solar eclipse glasses</a> with filters designed specifically for observing the partial eclipse are safe to use. They are easily available <a href="https://www.cnn.com/cnn-underscored/outdoors/best-solar-eclipse-glasses?cid=ios_app">from a variety of sources</a>, and you can wear them by themselves or over your glasses or contact lenses. </p>
<p>Keep in mind that these safety filters will permit you to view only the eclipse, as they blacken out everything around you but the Sun itself. Before purchasing a pair, make sure your eclipse glasses are approved by the <a href="https://eclipse.aas.org/eye-safety/iso-certification">ISO 12312-2 international standard</a>.</p>
<p>Only during its <a href="https://eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html">period of totality</a>, the time when the Sun is fully behind the Moon, is it safe to remove your filtered glasses – and then only with caution.</p>
<p>This year, totality will last an unusually long <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/">four and a half minutes</a>. If you leave your eclipse glasses on, you will miss seeing the Sun’s bright ring, or corona, behind the Moon. But then, as the Moon moves on, the sky will brighten and you’ll need to put the eclipse glasses back on.</p>
<h2>Eyes and light</h2>
<p>While the pupils of our eyes naturally constrict to limit bright light, and our eyes have pigments to absorb light, direct sunlight overwhelms these functions. Even viewing the Sun for a few brief moments <a href="https://theconversation.com/turn-around-bright-eyes-heres-how-to-see-the-eclipse-and-protect-your-vision-203571">can cause permanent vision loss</a>. </p>
<p>The Sun emits intense <a href="https://www.britannica.com/science/sunlight-solar-radiation">ultraviolet and infrared light</a>, which, while not visible to the human eye, can burn sensitive ocular tissues, such as the cornea and retina.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram of an eye as viewed from the side." src="https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=486&fit=crop&dpr=1 600w, https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=486&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=486&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=611&fit=crop&dpr=1 754w, https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=611&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/581353/original/file-20240312-24-e55u1i.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=611&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The cornea is the clear front surface of the eye, which lets light in. The retina is the inner lining of the back part of the eye, which sends signals to your brain, allowing you to see.</span>
<span class="attribution"><a class="source" href="https://aapos.org/glossary/how-to-safely-view-a-solar-eclipse">American Association for Pediatric Ophthalmology and Strabismus</a></span>
</figcaption>
</figure>
<p>Corneal damage from sunlight, called <a href="https://www.mayoclinic.org/diseases-conditions/actinic-keratosis/symptoms-causes/syc-20354969">solar keratosis</a>, can blur vision and be quite painful. While the cornea can heal itself, it may require several days to get better and lead to lost time at work or school. </p>
<p>Retinal damage, called <a href="https://www.health.wa.gov.au/Articles/S_T/Solar-retinopathy">solar retinopathy</a>, occurs inside the eye. While it isn’t painful, it can be more severe than corneal damage and can dramatically impair vision. Solar retinopathy symptoms include a blind spot in one’s central vision, visual distortions and altered color vision. </p>
<p>In mild cases, these symptoms may go away, but in more severe cases, and even with treatment, <a href="https://aapos.org/glossary/how-to-safely-view-a-solar-eclipse">they may become permanent</a>. </p>
<p>To both enjoy the eclipse and prevent eye damage, make sure you and your loved ones all view the event with strict proper precautions.</p><img src="https://counter.theconversation.com/content/221381/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoffrey Bradford does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Now’s the time to get your hands on a pair of eclipse glasses in preparation for April’s display of celestial wonder.Geoffrey Bradford, Professor of Pediatrics and Ophthalmology, West Virginia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2227092024-03-11T20:26:45Z2024-03-11T20:26:45ZArcheoastronomy uses the rare times and places of previous total solar eclipses to help us measure history<figure><img src="https://images.theconversation.com/files/580911/original/file-20240311-28-ygi764.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1280%2C1280&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A photograph of the 2017 total solar eclipse, taken at the Oregon State Fair Grounds, Salem, Ore.</span> <span class="attribution"><span class="source">(Dominic Hart/NASA)</span></span></figcaption></figure><p>In 648 BCE, the Greek poet Archilochus wrote that, “nothing can be surprising any more or impossible or miraculous, now that Zeus, father of the Olympians has <a href="https://articles.adsabs.harvard.edu/pdf/2020JAHH...23...47S">made night out of noonday</a>, hiding the light of the gleaming Sun.”</p>
<p>Total solar eclipses have fascinated and terrified people for centuries. Today, we know that total solar eclipses — like the <a href="https://theconversation.com/on-april-8-2024-parts-of-ontario-quebec-the-maritimes-and-newfoundland-will-see-a-total-eclipse-of-the-sun-heres-how-to-get-ready-for-it-203382">upcoming eclipse on April 8</a> — are caused by a cosmic coincidence when the moon comes between the Earth and the sun, momentarily blocking the sun from view. But in ancient times, the cause was unknown.</p>
<p>Nevertheless, the peoples of those eras took note. From all ends of the Earth, stories abound of day turning to night or <a href="https://eclipse2017.nasa.gov/eclipse-history">the sun being consumed</a>, and these records are opening up a new branch of study.</p>
<p><a href="https://www.jstor.org/stable/20170165">Astroarcheology</a> — also called archeoastronomy — uses astronomical records to help date key moments or events in history. Of all astronomical phenomena, total solar eclipses are among the best measuring sticks because they are only visible at a certain time and place. </p>
<p>Total solar eclipses are rare enough that a given spot on Earth is only likely to see <a href="https://articles.adsabs.harvard.edu/pdf/1982JBAA...92..124M">one every 375 years (on average)</a>. And when an eclipse does happen, it only appears as total to those who are <a href="https://eclipsewise.com/solar/SEatlas/SEatlas.html">along a narrow path on Earth</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="(drawing of a solar eclipse represented by a black circle surrounded by a white aura on a black background)" src="https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580844/original/file-20240310-26-te2a9p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An illustration of the solar eclipse that occurred on Jan. 22, 1898 in India.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Solar_eclipse_of_January_22,_1898">(Edward Walter Maunder/British Astronomical Association)</a></span>
</figcaption>
</figure>
<h2>Identifying years</h2>
<p>This combination of rare time and place helps researchers narrow down the exact date ancient peoples viewed a recorded eclipse. Additional clues such as the time of day the eclipse occurred (morning, noon or evening), time of year (season) or the presence of bright planets can also help identify the exact eclipse.</p>
<p>For example, a record of total solar eclipse occurring near dawn in ancient Chinese texts pertaining to King Yi helped <a href="https://articles.adsabs.harvard.edu/pdf/2003JAHH....6...53L">identify the year his reign began</a>.</p>
<p>One of the oldest recorded eclipses is on a clay tablet from the city of <a href="https://www.britannica.com/place/Ugarit">Ugarit, in modern-day Syria</a>. The city was overthrown after the eclipse, making the tablet one of the last things written down by someone from that city. The inscription on the tablet reads: “… day of the new moon in ḫiyaru the Sun went down, its gate-keeper was [Rashap].”</p>
<p>The word ḫiyaru refers to a time of year around February/March, and Rashap is likely a planet. Armed with this information and knowledge that the city disappeared in the Bronze Age, researchers dated the tablet and eclipse to March 5, 1222 BCE, over 3,000 years ago, with the planet Mars <a href="https://doi.org/10.1038/338238a0">visible near to the eclipsed sun</a>. Thanks to this eclipse, we know that Ugarit fell after March 5, 1222 BCE. </p>
<p>Records like these help researchers identify precise dates in the ancient world.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="an illustration of text above a photograph of a grey clay tablet" src="https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=689&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=689&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=689&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=866&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=866&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580919/original/file-20240311-17800-m97ekg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=866&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Photograph and illustration of the clay tablet KTU 1.78 from Ugarit, in modern-day Syria, which mentions a total solar eclipse.</span>
<span class="attribution"><span class="source">(Dietrich and Loretz/University of Chicago Library)</span></span>
</figcaption>
</figure>
<h2>Changing predictions</h2>
<p>Precisely predicting future eclipses, or plotting the paths of historical eclipses, requires knowing the positions of the sun, moon and Earth. Computers can track the motions of each, but the challenge here is that these motions are not constant. As the moon causes tides in Earth’s oceans, the process also causes the moon to slowly drift away from the Earth and <a href="https://www.scientificamerican.com/article/earth-rotation-summer-solstice/">the length of day on Earth to slowly increase</a>. </p>
<p>Essentially, the length of a day on Earth is getting longer by roughly 18 microseconds every year, <a href="http://dx.doi.org/10.1098/rspa.2016.0404">or one second every 55,000 years</a>. After hundreds or thousands of years, that fraction of a second per day adds up to several hours.</p>
<p>The change in Earth’s day also affects dating historical eclipses — if the difference in the length of day is not corrected for, calculations may be inaccurate by thousands of kilometers. As such, when using eclipses to date historical events a correction must be applied; uncertainties in the correction can make <a href="https://doi.org/10.1093/pasj/56.1.215">ancient eclipse identifications</a> harder to pin down in the absence of <a href="https://www.jstor.org/stable/178278">additional information</a> to help <a href="https://articles.adsabs.harvard.edu/pdf/1995QJRAS..36..397Z">narrow down the possibilities</a>. </p>
<h2>Measuring changing day-lengths</h2>
<p>For those solar eclipses that are well established, they open a window into tracking Earth’s length-of-day across the centuries. By timing eclipses over the last 2,000 years, researchers have mapped out the length of Earth’s day over that same span. The value of 18 microseconds per year is an average, but sometimes the Earth slows down a bit more and sometimes a bit less. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a graph showing day lengths over time" src="https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/580922/original/file-20240311-139405-bs1pct.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Change in length of day (lod) for Earth in milliseconds (0.001 s) as measured from eclipse records (black line). The red line shows the average change over 2,000 years, while the grey line shows what we would expect from tidal forces between the Earth and moon only. The green dashed line shows a model fit to the data in black.</span>
<span class="attribution"><a class="source" href="http://dx.doi.org/10.1098/rspa.2016.0404">(F.R. Stephenson, L.V. Morrison and C.Y. Hohenkerk)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Tides alone can’t explain this pattern — there is something more going on between the moon and the Earth, and the cause is still unknown. This mystery, however, can be explored thanks to solar eclipses. </p>
<p>We can measure a change in length of a day on Earth with instruments now, but we wouldn’t be able to capture that change hundreds or thousands of years back in time without a precise measuring stick and records of eclipses over millennia and across the world. Total solar eclipses allow us to peer into not only our own history, but the history of the Earth itself.</p><img src="https://counter.theconversation.com/content/222709/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Sadavoy receives funding from the National Sciences and Engineering Research Council of Canada (NSERC). </span></em></p>Mentions of total solar eclipses in ancient history help researchers pinpoint precise dates of notable events.Sarah Sadavoy, Assistant Professor, Physics, Engineering Physics & Astronomy, Queen's University, OntarioLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2208242024-03-08T14:35:38Z2024-03-08T14:35:38ZApril’s eclipse will mean interruptions in solar power generation, which could strain electrical grids<figure><img src="https://images.theconversation.com/files/573902/original/file-20240206-16-om8k0f.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3994%2C2658&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar panels in Brazil. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/7551d26521224cbf94340e255374a7a7?ext=true">AP Photo/Bruna Prado</a></span></figcaption></figure><p>During the most recent total solar eclipse visible in the U.S., on Aug. 21, 2017, the skies darkened as the Moon crossed in front of the Sun. It blocked out all sunlight – except for that from a golden ring visible around the Moon’s shape, called the corona. Not surprisingly, solar power generation across North America plummeted for several hours, from the first moment the Moon began to obscure the Sun to when the Sun’s disk was clear again. </p>
<p>On April 8, 2024, another <a href="https://theconversation.com/when-the-sun-goes-dark-5-questions-answered-about-the-solar-eclipse-81308">total solar eclipse</a> will track across the U.S., causing perhaps an even greater loss of solar power generation. Although this will be the second total solar eclipse visible in the U.S. in under seven years, these events are a rare occurrence. Nevertheless, they present a unique challenge to power grid operators.</p>
<p><a href="https://dornsife.usc.edu/profile/vahe-peroomian/">I am a space scientist</a> with a passion for teaching physics and astronomy. Though I have seen many partial eclipses of the Sun, I have yet to witness a total solar eclipse. My road trip to Bryce Canyon National Park in Utah in October 2023 to see the “ring of fire” <a href="https://theconversation.com/explainer-what-is-a-solar-eclipse-33019">annular solar eclipse</a> was unforgettable, and April 8 will surely find me handing out <a href="https://theconversation.com/turn-around-bright-eyes-heres-how-to-see-the-eclipse-and-protect-your-vision-203571">eclipse glasses</a> once again.</p>
<h2>When the Moon’s shadow blocks the Sun</h2>
<p>During <a href="https://theconversation.com/explainer-what-is-a-solar-eclipse-33019">a solar eclipse</a>, the Moon partially or completely blocks the view of the Sun. Since the Moon is nearly 400 times smaller than the Sun and nearly <a href="https://www.universetoday.com/17109/the-sun-and-the-moon/">400 times closer</a>, the <a href="https://www.forbes.com/sites/startswithabang/2017/02/08/the-strangest-eclipse-fact-of-all-the-moons-shadow-isnt-a-circle/?sh=be76f8c17bd3">Moon’s shadow</a>, visible from Earth, tapers to a width of <a href="https://cmase.uark.edu/_resources/pdf/nasa/NASAConnect/pathoftotality.pdf">70 to 100 miles</a> (112 to 161 kilometers).</p>
<p>Within this region, called the path of totality, observers see a total solar eclipse. Observers close to but outside this path witness a partial eclipse of the Sun, where the Moon covers a fraction of the Sun’s disk. </p>
<p>During the April 8, 2024, total solar eclipse, the <a href="https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/where-when/">path of totality</a> in the continental U.S. will extend from Texas in the south to Maine in the northeast. Elsewhere in the U.S., Miami will see a partial eclipse in which a maximum of 46% of the Sun’s disk is obscured. In Seattle, far from the path of totality, the Moon will cover only a maximum of <a href="https://www.timeanddate.com/eclipse/map/2024-april-8">20% of the Sun</a>. In southern Texas, where the path of totality first crosses into the U.S., the eclipse will last just under three hours, with totality a mere 4 minutes and 27 seconds. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sOpYoO_SK7o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The path of the 2024 solar eclipse.</span></figcaption>
</figure>
<h2>Increasing reliance on solar power</h2>
<p>The worldwide trend toward renewable energy has seen a significant increase in solar, or photovoltaic, power generation in the last decade. Solar power generation capacity is set to <a href="https://www.iea.org/data-and-statistics/data-tools/renewable-energy-progress-tracker">double worldwide</a> between 2022 and 2028, and the U.S. now has the capacity to generate <a href="https://ember-climate.org/data-catalogue/yearly-electricity-data/">three times more solar energy</a> than at the time of the 2017 total solar eclipse.</p>
<p>The most obvious obstacle to solar power generation is cloud cover. On a cloudy day, the energy produced by solar panels drops to <a href="https://www.forbes.com/home-improvement/solar/solar-panels-cloudy-days-night/">10% to 25%</a> of its output on a sunny day. </p>
<p>The North American power transmission grid is divided into <a href="https://www.nerc.com/AboutNERC/keyplayers/Pages/default.aspx">six major regions</a> and <a href="https://alternativeenergy.procon.org/questions/what-is-the-electricity-grid/">more than 150</a> local and regional subgrids. Electrical system operators in each local grid continuously balance the amount of electricity production with the “load,” or the demand for electricity by consumers. </p>
<p>System operators can tap into energy from <a href="https://science.howstuffworks.com/environmental/energy/power.htm">various power generation mechanisms</a> like solar, wind, hydroelectric, natural gas and coal. Local grids can also import and export electricity to and from their grid as needed.</p>
<p>System operators have accurate models for the amount of solar power generated across the U.S. on a daily basis, and these models account for the parts of the continental U.S. that may have cloudy skies. By pairing solar power generation with battery storage, they can access electricity from solar even when the Sun isn’t shining – on cloudy days or at night. </p>
<p>To plan for an eclipse, electrical system operators need to figure out how much the energy production will drop and how much power people will draw from the reserves. On the day of the 2017 total solar eclipse, for example, solar power generation in the U.S. <a href="https://www.nrel.gov/docs/fy18osti/71147.pdf">dropped 25%</a> below average. </p>
<p>Because solar power production falls quickly during the eclipse’s peak, grid operators may need to tap into reserves at a rate that may strain the <a href="https://www.osha.gov/etools/electric-power/illustrated-glossary/transmission-lines">electrical transmission lines</a>. To try to keep things running smoothly, grid operators will rely on local reserves and minimize power transfer <a href="https://www.nrel.gov/docs/fy18osti/71147.pdf">between grids</a> during the event. This should lessen the burden on transmission lines in local grids and prevent temporary blackouts. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Electrical towers and power lines shown against a sunset." src="https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573903/original/file-20240206-28-khlo8k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Solar eclipses can stress the power grid.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/BidenInfrastructure/9a4ee5858ac74db78eb7d96b1961c275/photo?Query=power%20grid&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=226&digitizationType=Digitized&currentItemNo=17&vs=true&vs=true">AP Photo/Matt Rourke</a></span>
</figcaption>
</figure>
<h2>Renewable energy during eclipses</h2>
<p>Solar isn’t the only type of renewable energy generation that goes down during an eclipse. Since it’s not as sunny, temperatures along the path of the eclipse fall by as much as <a href="https://eclipse2017.nasa.gov/temperature-change-during-totality">10 degrees Fahrenheit</a> (5.5 degrees Celsius). Lower temperatures lead to <a href="https://doi.org/10.1093/astrogeo/atx135">slower wind speeds</a> and less wind power generation. </p>
<p>During the August 2017 eclipse, the loss of renewable power generation added up to nearly <a href="https://www.nrel.gov/docs/fy18osti/71147.pdf">6 gigawatts</a>. That’s equivalent to the energy usage of <a href="https://www.energy.gov/eere/articles/how-much-power-1-gigawatt">600 million LED lightbulbs</a> or <a href="https://www.cnet.com/home/energy-and-utilities/gigawatt-the-solar-energy-term-you-should-know-about/">4.5 million homes</a>. </p>
<p>Grid operators compensated by planning ahead and increasing power generation at <a href="https://www.nrel.gov/docs/fy18osti/71147.pdf">natural gas and coal-powered plants</a>, which don’t depend on sunlight. </p>
<p>Over the duration of the eclipse, this increase in nonrenewable energy use led to approximately <a href="https://www.eia.gov/tools/faqs/faq.php?id=74&t=11">10 million pounds</a> of extra carbon dioxide emissions. That’s about the annual carbon dioxide emissions of 1,000 cars.</p>
<p>On April 8, <a href="https://theconversation.com/astro-tourism-chasing-eclipses-meteor-showers-and-elusive-dark-skies-from-earth-207969">eyes across the U.S. will turn upward</a> to catch a glimpse of the eclipsed Sun.</p>
<p>Thanks to the vigilance of electric grid operators, the lights should stay on, and observers won’t have to worry about anything but the stunning show in the sky.</p><img src="https://counter.theconversation.com/content/220824/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vahe Peroomian has, in the past, received basic research funding from NASA and the National Science Foundation.</span></em></p>When the Moon blocks the Sun during an eclipse, utility suppliers have to pull power from the grid to make up for gaps in solar energy.Vahe Peroomian, Professor of Physics and Astronomy, USC Dornsife College of Letters, Arts and SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2243872024-03-06T17:45:13Z2024-03-06T17:45:13ZSpacesuits need a major upgrade for the next phase of exploration<figure><img src="https://images.theconversation.com/files/579865/original/file-20240305-18-mik4ri.jpg?ixlib=rb-1.1.0&rect=11%2C0%2C3822%2C2160&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/news-release/nasa-taps-axiom-space-for-first-artemis-moonwalking-spacesuits/">NASA</a></span></figcaption></figure><p>Humans have long dreamed of setting foot on the Moon and other planetary bodies such as Mars. Since the 1960s, space travellers have donned suits designed to protect them from the vacuum of space and stepped out into the unknown.</p>
<p>However, <a href="https://spacenews.com/polaris-dawn-private-astronaut-mission-slips-to-mid-2024/">the Polaris Dawn mission</a>, which is to include the first spacewalk organised by a private company, has been delayed. This is due to complications with the design and development of a suitable spacesuit. </p>
<p>Moon suits are also one of the key elements of Nasa’s Artemis lunar programme that have yet to be delivered. A report released in November 2023 said that the contractor making the suits is having <a href="https://www.gao.gov/products/gao-24-106256#:%7E:text=To%20develop%20Artemis%20space%20suits,report%20examining%20the%20Artemis%20enterprise.">to revisit aspects of the design provided by Nasa</a>, which could introduce delays.</p>
<p>Yet <a href="https://time.com/5802128/alexei-leonov-spacewalk-obstacles/">the first spacewalk</a>, by the Soviet cosmonaut Alexei Leonov, took place in 1965. Later, <a href="https://www.nasa.gov/the-apollo-program/">12 Nasa astronauts would walk on the lunar surface</a>, between 1969 and 1972, using technology that would be eclipsed by today’s smartphones. So it’s not unreasonable to ask why it can still be difficult to design and build spacesuits to do the same thing.</p>
<p>Much has changed since the Apollo missions planted flags on the Moon. The <a href="https://www.cnbc.com/video/2024/01/20/us-china-india-japan-and-others-are-rushing-back-to-the-moon.html">geopolitics driving space travel have shifted</a>, and spacesuits are no longer expected to be just a form of protection. Instead, they are a critical way to improve the productivity of astronauts. This involves a rethink of not just the suits themselves, but the technology that supports them.</p>
<figure class="align-center ">
<img alt="Crew Dragon approaching the ISS" src="https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579872/original/file-20240305-30-sdnkjj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Polaris Dawn mission uses modified version of the Crew Dragon spacecraft to perform the first commercial spacewalk.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/image-article/view-of-spacex-crew-dragon-endeavour-approaching-station/">Nasa</a></span>
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<p>An array of powerful telecommunications technologies to connect astronauts with space stations and ground control sits alongside multisensory cameras, temperature readers and proximity sensors in present-day spacesuits.</p>
<p>Situational awareness – understanding key elements in the environment, such as the health of an astronaut – is a core tenet for modern spacesuit design and critical for the operator’s safety. The ability of a suit to track heart rate and other vital signs is important in a vacuum, where levels of oxygen need constant monitoring. </p>
<p>Expectations around the risks astronauts take have changed for the better. And the level of investment it takes to produce a spacesuit necessitates that it can be used for future tasks that may include lunar settlement in the next few decades.</p>
<p>The trade off that engineers must make when incorporating wearable technology like those already mentioned is weight. Will greater situational awareness result in a spacesuit that is too heavy to move in effectively? </p>
<p>When Elon Musk first hinted at challenges with the extravehicular activity spacesuit for Polaris Dawn <a href="https://twitter.com/SpaceX/status/1745941814165815717">in a presentation to SpaceX employees in January</a>, it was not difficulties with connected technology that he discussed, but of redesigning “the suit so that you actually move around in it”.</p>
<h2>Situational awareness</h2>
<p>However, when talking about mobility in a spacesuit, you need to consider the tasks that you want that mobility to support. </p>
<p>Before the advent of modern spacesuits, Apollo astronauts struggled to carry out missions. When drilling into the surface of the Moon with a hand drill to collect samples, astronauts found it difficult to provide enough downwards force to counteract the Moon’s weaker gravity. It was not until the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576522002879">invention of a zero-gravity drill</a>, decades later, that this problem would be addressed.</p>
<p>The current exploration of <a href="https://digital-library.theiet.org/content/books/ce/pbce131e">pneumatic exoskeletons</a>, providing the support necessary for movement in low gravity could be part of a solution. However, newer spacesuits may also need to interface with hardware, like robotic drills that exist outside the suit. This will also necessitate more mobility in spacesuits. </p>
<h2>Working with robots</h2>
<p>Offloading tasks, previously carried out by humans, to robots will be part of the future of space exploration. It’s a primary way that engineers will also be able to enhance the mobility of astronauts in spacesuits.</p>
<p>For example, when an astronaut goes on a spacewalk to inspect the condition of part of a space station and make any possible repairs, they are supported by a robotic arm that ensures they don’t float off into space. While jointed, this arm is rigid and can limit an astronaut’s movement.</p>
<p>An approach currently being explored to extend this range of movement is a climbing robot, that is attached to both the astronaut and the space station, that an individual can control through their spacesuit. This would allow the astronaut to move around the space station faster and with a greater range of movement than before, allowing them to reach and repair hard-to-access areas like corners.</p>
<p>While the eventual hope is that robots themselves can assess any damage to the space station and repair it, due to possible disruptions in normal operations, humans must be ready to step in. Possible disruptions could be natural, like a small meteor shower damaging the robot, or human-made, like hacking carried by a hostile group or state.</p>
<p>For the types of activities we want to accomplish in the future, this human-robot collaboration will be instrumental. Building a base on the Moon, as both <a href="https://www.smithsonianmag.com/science-nature/four-things-weve-learned-about-nasas-planned-base-camp-on-the-moon-180980589/">the US</a> and <a href="https://spacenews.com/china-attracts-moon-base-partners-outlines-project-timelines/">China</a> plan to do, will involve construction work and drilling, which humans will not be able to accomplish alone. Modern spacesuits will need to provide an interface to work with this new technology, and we can expect the suits to evolve in step with robotics.</p>
<p>The relationship between humans and robots is changing. It will go beyond spacewalks and robots’ previous uses as limited tools, to a situation where they are cooperative partners in space. The objectives of ten or 20 years from now, like building lunar settlements, exploring mineral deposits on the Moon and efficiently repairing space station modules can only be achieved using robotics. </p>
<p>Modern spacesuits will be a key foundation of this collaborative relationship, forming the interface where astronauts and robots can work together to achieve shared goals. So when we do once again leave our footprints on other worlds, we will no longer be alone.</p><img src="https://counter.theconversation.com/content/224387/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yang Gao has received funding from UKRI, UKSA and ESA on conducting space related research. </span></em></p>The next generation of spacesuit needs to do more than simply protect an astronaut from the vacuum of space.Yang Gao, Professor of Robotics, Head of Centre for Robotics Research, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2245032024-02-28T01:00:24Z2024-02-28T01:00:24ZLeap of imagination: how February 29 reminds us of our mysterious relationship with time and space<p>If you find it intriguing that February 28 will be followed this week by February 29, rather than March 1 as it usually is, spare a thought for those alive in 1582. Back then, Thursday October 4 was followed by Friday October 15.</p>
<p>Ten whole days were snatched from the present when Pope Gregory XIII issued a papal bull to “restore” the calendar from discrepancies that had crept into the Julian calendar, introduced by Julius Caesar in 45 BCE.</p>
<p>The new Gregorian calendar returned the northern hemisphere’s vernal equinox to its “proper” place, around March 21. (The equinox is when the Earth’s axis is tilted neither toward nor away from the sun, and is used to determine the date of Easter.) </p>
<p>The Julian calendar had observed a leap year every four years, but this meant time had drifted out of alignment with the dates of celestial events and astronomical seasons. </p>
<p>In the Gregorian calendar, leap days were added only to years that were a multiple of four – like 2024 – with an exception for years that were evenly divisible by 100, but not 400 – like 1700.</p>
<p>Simply put, leap days exist because it doesn’t take a neat 365 days for Earth to orbit the Sun. It takes 365.2422 days. Tracking the movement of celestial objects through space in an orderly pattern doesn’t quite work, which is why we have February – time’s great mop.</p>
<h2>Time and space</h2>
<p>This is just part of the history of how February – the shortest month, and originally the last month in the Roman calendar – came to have the job of absorbing those inconsistencies in the temporal calculations of the world’s most commonly used calendar.</p>
<p>There is plenty of <a href="https://theconversation.com/leap-day-fixing-the-faults-in-our-stars-54032">science</a>, <a href="https://theconversation.com/explainer-the-science-behind-leap-years-and-how-they-work-54788">maths</a> and <a href="https://theconversation.com/how-a-seasonal-snarl-up-in-the-mid-1500s-gave-us-our-strange-rules-for-leap-years-132659">astrophysics</a> explaining the relationship between time and the planet we live on. But I like to think leap years and days offer something even more interesting to consider: why do we have calendars anyway?</p>
<p>And what have they got to do with how we understand the wonder and strangeness of our existence in the universe? Because calendars tell a story, not just about time, but also about space.</p>
<p>Our reckoning of time on Earth is through our spatial relationship to the Sun, Moon and stars. Time, and its place in our lives, sits somewhere between the scientific, the celestial and the spiritual. </p>
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<p>It is <a href="https://shop.whitechapelgallery.org/products/time">notoriously slippery, subjective and experiential</a>. It is also marked, tracked and determined in myriad ways across different cultures, from tropical to solar to <a href="https://www.stuff.co.nz/pou-tiaki/300062097/matariki-and-the-maramataka-the-mori-lunar-calendar">lunar</a> calendars.</p>
<p>It is the Sun that measures a day and gives us our first reference point for understanding time. But it is the <a href="https://librarysearch.aut.ac.nz/vufind/Record/1145999?sid=25214690">Moon</a>, as a major celestial body, that extends our perception of time. By stretching a span of one day into something longer, it offers us a chance for philosophical reflection.</p>
<p>The Sun (or its effect at least) is either present or not present. The Moon, however, goes through phases of transformation. It appears and disappears, changing shape and hinting that one night is not exactly like the one before or after.</p>
<p>The Moon also has a distinct rhythm that can be tracked and understood as a pattern, giving us another sense of duration. Time is just that – overlapping durations: instants, seconds, minutes, hours, days, weeks, months, years, decades, lifetimes, centuries, ages.</p>
<h2>The elusive Moon</h2>
<p>It is almost impossible to imagine how time might feel in the absence of all the tools and gadgets we use to track, control and corral it. But it’s also hard to know what we might do in the absence of time as a unit of productivity – a measurable, dispensable resource.</p>
<p>The closest we might come is simply to imagine what life might feel like in the absence of the Moon. Each day would rise and fall, in a rhythm of its own, but without visible reference to anything else. Just endless shifts from light to dark.</p>
<p>Nights would be almost completely dark without the light of the Moon. Only stars at a much further distance would puncture the inky sky. The world around us would change – trees would grow, mammals would age and die, land masses would shift and change – but all would happen in an endless cycle of sunrise to sunset.</p>
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Read more:
<a href="https://theconversation.com/scientists-are-hoping-to-redefine-the-second-heres-why-157645">Scientists are hoping to redefine the second – here's why</a>
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<p>The light from the Sun takes <a href="https://www.skyatnightmagazine.com/space-science/how-take-light-from-sun-reach-earth">eight minutes</a> to reach Earth, so the sunlight we see is always eight minutes in the past. </p>
<p>I remember sitting outside when I first learned this, and wondering what the temporal delay might be between me and other objects: a plum tree, trees at the end of the street, hills in the distance, light on the horizon when looking out over the ocean, stars in the night sky.</p>
<p>Moonlight, for reference, takes about <a href="https://www.pbs.org/seeinginthedark/astronomy-topics/light-as-a-cosmic-time-machine.html">1.3 seconds</a> to get to Earth. Light always travels at the same speed, it is entirely constant. The differing duration between how long it takes for sunlight or moonlight to reach the Earth is determined by the space in between. </p>
<p>Time on the other hand, is anything but constant. There are countless ways we characterise it. The mere fact we have so many calendars and ways of describing perceptual time hints at our inability to pin it down. </p>
<p>Calendars give us the impression we can, and have, made time predictable and understandable. Leap years, days and seconds serve as a periodic reminder that we haven’t.</p><img src="https://counter.theconversation.com/content/224503/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily O'Hara does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>2024 is a leap year, when the shortest month mops up a bit of leftover time. But the extra day also tells us about space – and our place in it.Emily O'Hara, Senior Lecturer, Spatial Design + Temporary Practices, Auckland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2242762024-02-27T00:36:58Z2024-02-27T00:36:58ZThe US just returned to the Moon after more than 50 years. How big a deal is it, really?<figure><img src="https://images.theconversation.com/files/577849/original/file-20240226-20-dqo1ws.jpg?ixlib=rb-1.1.0&rect=9%2C6%2C2035%2C1526&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/intuitivemachines/53534907523/">Intuitive Machines</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>In the few short years since the COVID pandemic changed our world, China, Japan and India have all successfully landed on the Moon. </p>
<p>Many more robotic missions have flown past the Moon, entered lunar orbit, or crashed into it in the past five years. This includes <a href="https://www.planetary.org/space-missions/kplo">spacecraft developed by South Korea</a>, <a href="https://english.alarabiya.net/News/gulf/2023/04/27/Dubai-s-ruler-announces-new-moon-mission-after-UAE-s-Rashid-Rover-lunar-crash-">the United Arab Emirates</a>, and an <a href="https://www.spaceil.com/">Israeli not-for-profit organisation</a>. </p>
<p>Late last week, the American company <a href="https://www.intuitivemachines.com/">Intuitive Machines</a>, in collaboration with NASA, celebrated “America’s return to the Moon” with a successful landing of its Odysseus spacecraft.</p>
<p>Recent <a href="https://theconversation.com/change-5-china-launches-sample-return-mission-to-the-moon-is-it-winning-the-new-space-race-150665">Chinese-built sample return missions</a> are far more complex than this project. And didn’t NASA ferry a dozen humans to the Moon back when microwaves were cutting-edge technology? So what is different about this mission developed by a US company?</p>
<h2>Back to the Moon</h2>
<p>The recent Odysseus landing stands out for two reasons. For starters, this is the first time a US-built spacecraft has landed – not crashed – on the Moon for over 50 years. </p>
<p>Secondly, and far more significantly, this is the first time a private company has pulled off a successful delivery of cargo to the Moon’s surface.</p>
<p>NASA has lately focused on destinations beyond the Earth–Moon system, including Mars. But with its <a href="https://www.nasa.gov/commercial-lunar-payload-services/">Commercial Lunar Payload Services</a> (CLPS) program, it has also funded US private industry to develop Moon landing concepts, hoping to reduce the delivery costs of lunar payloads and allow NASA engineers to focus on other challenges. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/us-moon-landing-marks-new-active-phase-of-lunar-science-with-commercial-launches-of-landers-that-will-study-solar-wind-and-peer-into-the-universes-dark-ages-219892">US Moon landing marks new active phase of lunar science, with commercial launches of landers that will study solar wind and peer into the universe’s dark ages</a>
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<p>Working with NASA, Intuitive Machines selected a <a href="https://en.wikipedia.org/wiki/Malapert_(crater)">landing site</a> about 300 kilometres from the lunar south pole. Among other challenges, landing here requires entering a polar orbit around the Moon, which consumes additional fuel.</p>
<p>At this latitude, the land is heavily cratered and dotted with long shadows. This makes it challenging for autonomous landing systems to find a safe spot for a touchdown.</p>
<p>NASA spent about US$118 million (A$180 million) to land six scientific <a href="https://www.esa.int/Enabling_Support/Space_Engineering_Technology/About_Payload_Systems">payloads</a> on Odysseus. This is relatively cheap. Using low-cost lunar landers, NASA will have an efficient way to test new space hardware that may then be flown on other Moon missions or farther afield.</p>
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<h2>Ten minutes of silence</h2>
<p>One of the technology tests on the Odysseus lander, NASA’s <a href="https://www.nasa.gov/directorates/stmd/impact-story-navigation-doppler-lidar/">Navigation Doppler Lidar experiment</a> or NDL, appears to have proved crucial to the lander’s success.</p>
<p>As the lander neared the surface, the company realised its navigation systems had a problem. NASA’s NDL experiment is serendipitously designed to test precision landing techniques for future missions. It seems that at the last second, engineers bodged together a solution that involved feeding necessary data from NDL to the lander.</p>
<p>Ten minutes of silence followed before a <a href="https://twitter.com/Int_Machines/status/1760838333851148442">weak signal was detected</a> from Odysseus. Applause thundered through the mission control room. NASA’s administrator released a video congratulating everyone for returning America to the Moon. </p>
<p>It has since become clear the lander is not oriented perfectly upright. The solar panels are generating sufficient power and the team is slowly receiving the first images from the surface.</p>
<p>However, it’s likely Odysseus <a href="https://www.universetoday.com/165864/odysseus-moon-lander-is-tipped-over-but-still-sending-data/">partially toppled over</a> upon landing. Fortunately, at the time of writing, it seems most of the science payload may yet be deployed as it’s on the side of the lander facing upwards. The unlucky payload element facing downwards <a href="https://edition.cnn.com/2024/02/23/world/odysseus-lunar-landing-sideways-scn/index.html">is a privately contributed artwork</a> connected <a href="https://edition.cnn.com/2024/02/22/style/jeff-koons-moon-phases-odysseus-landing/index.html">to NFTs</a>.</p>
<p>The lander is now likely to survive for at least a week before the Sun sets on the landing site and a dark, frigid lunar night turns it into another museum piece of human technology frozen in the lunar <a href="https://www.britannica.com/science/regolith">regolith</a>.</p>
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<a href="https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up view of a machine with golden foil and various panels with a grey moon surface in the background" src="https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577850/original/file-20240226-22-o9u0r9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The Moon visible 10km beneath the Odysseus lander after it entered lunar orbit on February 21.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/intuitivemachines/53544280843/">Intuitive Machines</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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Read more:
<a href="https://theconversation.com/scientists-and-space-agencies-are-shooting-for-the-moon-5-essential-reads-on-modern-lunar-missions-216808">Scientists and space agencies are shooting for the Moon – 5 essential reads on modern lunar missions</a>
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<h2>Win some, lose some</h2>
<p>NASA’s commercial approach to stimulating low-cost payload services all but guarantees some failures. But eventually NASA hopes that several commercial launch and landing providers will emerge from the program, along with a few learning experiences.</p>
<p>The know-how accumulated at organisations operating hardware in space is at least as important as the development of the hardware itself.</p>
<p>The market for commercial lunar payloads remains unclear. Possibly, once the novelty wears off and brands are no longer able to generate buzz by, for example, <a href="https://www.columbia.com/omni-heat-infinity/moon-mission/">sending a piece of outdoor clothing to the Moon</a>, this source of funding may dwindle.</p>
<p>However, just as today, civil space agencies and taxpayers will continue to fund space exploration to address shared science goals.</p>
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<p>Ideally, commercial providers will offer NASA an efficient method for testing key technologies needed for its schedule of upcoming scientific robotic missions, as well as <a href="https://www.nasa.gov/specials/artemis/">human spaceflight in the Artemis program</a>. Australia would also have the opportunity to test hardware at a reduced price.</p>
<p>It’s worth noting that US budgetary issues, <a href="https://spacenews.com/nasa-warns-of-very-problematic-space-technology-budget-cuts/">funding cuts</a> and <a href="https://www.jpl.nasa.gov/news/jpl-workforce-update">subsequent lay-offs</a> do threaten these ambitions.</p>
<p>Meanwhile, in Australia, we may have nothing to launch anyway. We continue to spend less <a href="https://www.aph.gov.au/About_Parliament/Parliamentary_departments/Parliamentary_Library/Budget/reviews/2023-24/ScienceResearch">than the OECD average on scientific research</a>, and only a few Australian universities – who traditionally lead such efforts – <a href="https://business.gov.au/grants-and-programs/moon-to-mars-initiative-demonstrator-mission-grants/grant-recipients">have received funding</a> provided by the Australian Space Agency.</p>
<p>If we do support planetary science and space exploration in the future, Australians will need to decide if we want to allocate our limited resources, competing with NASA and US private industry, to supply launch, landing and robotic services to the global space industry.</p>
<p>Alternatively, we could leverage these lower-cost payload providers to develop our own scientific space program, and locally developed space technologies associated with benefits to the knowledge economy, education and national security.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-wants-a-space-industry-so-why-wont-we-pay-for-the-basic-research-to-drive-it-178878">Australia wants a space industry. So why won't we pay for the basic research to drive it?</a>
</strong>
</em>
</p>
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<img src="https://counter.theconversation.com/content/224276/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Flannery receives funding from the Australian Research Council and NASA. </span></em></p>A private company has successfully delivered cargo to the Moon’s surface for the first time. Here’s what that means for future space exploration.David Flannery, Planetary Scientist, Queensland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2243962024-02-26T15:44:21Z2024-02-26T15:44:21ZCould tardigrades have colonized the Moon?<p>Just over five years ago, on 22 February 2019, an unmanned space probe was placed in orbit around the Moon. Named <a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2019-009B"><em>Beresheet</em> and built by SpaceIL and Israel Aerospace Industries</a>, it was intended to be the first private spacecraft to perform a soft landing. Among the probe’s payload were tardigrades, renowed for their ability to survive in even the harshest climates.</p>
<p>The mission <a href="https://davidson.weizmann.ac.il/en/online/sciencepanorama/what-happened-beresheet">ran into trouble from the start</a>, with the failure of “star tracker” cameras intended to determine the spacecraft’s orientation and thus properly control its motors. Budgetary limitations had imposed a pared-down design, and while the command center was able to work around some problems, things got even trickier on 11 April, the day of the landing.</p>
<p>On the way to the Moon the spacecraft had been travelling at high speed, and it needed to be slowed way down to make a soft landing. Unfortunately during the braking manoeuvre a gyroscope failed, blocking the primary engine. <a href="https://spacenews.com/spaceil-says-chain-of-events-led-to-crash-of-lunar-lander/">At an altitude of 150 m, <em>Beresheet</em> was still moving at 3,000 km/h</a>, far too fast to be stopped in time. The impact was violent – the probe shattered and its remains were scattered over a distance of around a hundred metres. We know this because the site was photographed by NASA’s LRO (Lunar Reconnaissance Orbiter) satellite on 22 April.</p>
<p><a title="NASA/GSFC/Arizona State University/Wikimedia" href="https://commons.wikimedia.org/wiki/File :Beresheet_Crash_Site_Spotted_LRO_02.gif"><img width="512" alt="Beresheet crash site spotted by LRO 02" src="https://upload.wikimedia.org/wikipedia/commons/thumb/6/6b/Beresheet_Crash_Site_Spotted_LRO_02.gif/512px-Beresheet_Crash_Site_Spotted_LRO_02.gif"></a></p>
<h2>Animals that can withstand (almost) anything</h2>
<p>So what happened to the <a href="https://www.livescience.com/57985-tardigrade-facts.html">tardigrades</a> that were travelling on the probe? Given their remarkable abilities to survive situations that would kill pretty much any other animal, could they have contaminated the Moon? Worse, might they be able to reproduce and colonize it?</p>
<p>Tardigrades are microscopic animals that measure less than a millimetre in length. All have neurons, a mouth opening at the end of a retractable proboscis, an intestine containing a microbiota and four pairs of non-articulated legs ending in claws, and most have two eyes. As small as they are, they share a common ancestor with arthropods such as insects and arachnids.</p>
<p>Most tardigrades live in aquatic environments, but they can be found in any environment, even urban ones. <a href="https://biophysique.mnhn.fr/fr/annuaire/emmanuelle-delagoutte-9017">Emmanuelle Delagoutte</a>, a researcher at the CNRS, collects them in the mosses and lichens of the Jardin des Plantes in Paris. To be active, feed on microalgae such as chlorella, and move, grow and reproduce, tardigrades need to be surrounded by a film of water. They reproduce sexually or asexually via parthenogenesis (from an unfertilised egg) or even hermaphroditism, when an individual (which possesses both male and female gametes) self-fertilises. Once the egg has hatched, the active life of a tardigrade lasts from 3 to 30 months. A total of <a href="https://link.springer.com/book/10.1007/978-3-319-95702-9">1,265 species have been described</a>, including two fossils.</p>
<h2>Otherworldly powers</h2>
<p>Tardigrades are famous for their resistance to conditions that exist neither on Earth nor on the Moon. They can shut down their metabolism by losing up to 95% of their body water. Some species synthesise a sugar, trehalose, that <a href="https://www.nature.com/articles/s42003-022-04015-2">acts as an antifreeze</a>, while others synthesise proteins that are thought to incorporate cellular constituents into an amorphous “glassy” network that offers resistance and protection to each cell.</p>
<p>During dehydration, the tardigrade’s body can shrink to half its normal size. The legs disappear, with only the claws still visible. This state, known as <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cryptobiosis">cryptobiosis</a>, persists until conditions for active life become favourable again.</p>
<p>Depending on the species of tardigrade, individuals need more or less time to dehydrate and not all specimens of the same species manage to return to active life. Dehydrated adults survive for a few minutes at temperatures as low as -272°C or as high as 150°C, and over the long term at high doses of gamma rays of 1,000 or 4,400 Gray (Gy). By way of comparison, a dose of 10 Gy is fatal for humans, and 40-50,000 Gy sterilises all types of material. However, whatever the dose, radiation kills tardigrade eggs. What’s more, the protection afforded by cryptobiosis is not always clear-cut, as in the case of <em>Milnesium tardigradum</em>, where radiation affects both active and dehydrated animals in the same way.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=460&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=460&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=460&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=578&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=578&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577940/original/file-20240226-18-qtnl5g.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=578&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The species <em>Milnesium tardigradum</em> in its active state.</span>
<span class="attribution"><a class="source" href="https://fr.wikipedia.org/wiki/Tardigrada#/media/Fichier:SEM_image_of_Milnesium_tardigradum_in_active_state_-_journal.pone.0045682.g001-2.png">E. Schokraie, U. Warnken, A. Hotz-Wagenblatt, M.A. Grohme, S. Hengherr, et al. (2012).</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Lunar life?</h2>
<p>So what happened to the tardigrades after they crashed on the Moon? Are any of them still viable, buried under the moon’s <a href="https://en.wikipedia.org/wiki/Lunarsoil">regolith</a>, the dust that varies in depth from a few metres to several dozen metres?</p>
<p>First of all, they have to have survived the impact. <a href="https://pubmed.ncbi.nlm.nih.gov/33978458/">Laboratory tests</a> have shown that frozen specimens of the <em>Hypsibius dujardini</em> species travelling at 3,000 km/h in a vacuum were fatally damaged when they smashed into sand. However, they survived impacts of 2,600 km/h or less – and their “hard landing” on the Moon, unwanted or not, was far slower.</p>
<p>The Moon’s surface is not protected from solar particles and cosmic rays, particularly gamma rays, but here too, the tardigrades would be able to resist. In fact, Robert Wimmer-Schweingruber, professor at the University of Kiel in Germany, and his team have shown that the <a href="https://www.science.org/doi/10.1126/sciadv.aaz1334">doses of gamma rays hitting the lunar surface were permanent but low</a> compared with the doses mentioned above – 10 years’ exposure to Lunar gamma rays would correspond to a total dose of around 1 Gy.</p>
<p>But then there’s the question of “life” on the Moon. The tardigrades would have to withstand a lack of water as well as temperatures ranging from -170 to -190°C during the lunar night and 100 to 120°C during the day. A lunar day or night lasts a long time, just under 15 Earth days. The probe itself wasn’t designed to withstand such extremes and even if it hadn’t crashed, it would have ceased all activity after just a few Earth days.</p>
<p>Unfortunately for the tardigrades, they can’t overcome the lack of liquid water, oxygen and microalgae – they would never be able to reactivate, much less reproduce. Their colonising the Moon is thus impossible. Still, inactive specimens are on lunar soil and their presence raises ethical questions, as <a href="https://www.prindleinstitute.org/2019/09/the-ethics-of-sending-life-to-the-moon-and-beyond/">Matthew Silk</a>, an ecologist at the University of Edinburgh, points out. Moreover, at a time when space exploration is taking off in all directions, contaminating other planets could mean that we would lose the opportunity to detect extraterrestrial life.</p>
<hr>
<p><em>The author thanks Emmanuelle Delagoutte and Cédric Hubas of the Muséum de Paris, and Robert Wimmer-Schweingruber of the University of Kiel, for their critical reading of the text and their advice.</em></p><img src="https://counter.theconversation.com/content/224396/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laurent Palka ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Tardigrades are tiny animals known for their extraordinary survival skills, but are they tough enough to survive a space-probe crash and conditions on the Moon?Laurent Palka, Maître de conférences, Muséum national d’histoire naturelle (MNHN)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2183302024-02-19T13:36:56Z2024-02-19T13:36:56ZWhy does a leap year have 366 days?<figure><img src="https://images.theconversation.com/files/575717/original/file-20240214-24-h6q6if.jpg?ixlib=rb-1.1.0&rect=38%2C23%2C5137%2C3422&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Leap Day is coming.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/calendar-on-february-29-on-a-leap-year-leap-day-royalty-free-image/1196849410">Marvin Samuel Tolentino Pineda/iStock, via Getty images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p>Why does a leap year have 366 days? Does the Earth move slower every four years? – Aarush, age 8, Milpitas, California</p>
</blockquote>
<hr>
<p>You may be used to hearing that it takes the Earth 365 days to make a full lap, but that journey actually lasts about 365 and a quarter days. Leap years help to keep the 12-month calendar matched up with Earth’s movement around the Sun. </p>
<p>After four years, those leftover hours add up to a whole day. In a leap year, we add this extra day to the month of February, making it 29 days long instead of the usual 28.</p>
<p>The idea of an annual catch-up dates back to ancient Rome, where people had a calendar with 355 days instead of 365 because it was based on cycles and phases of the Moon. They noticed that their calendar was getting out of sync with the seasons, so they began adding an extra month, <a href="https://www.britannica.com/science/Roman-republican-calendar">which they called Mercedonius</a>, every two years to catch up with the missing days.</p>
<p>In the year 45 B.C.E., Roman emperor Julius Caesar introduced a solar calendar, based on one developed in Egypt. Every four years, February received an extra day to keep the calendar in line with the Earth’s journey around the Sun. In honor of Caesar, this system is still known as the Julian calendar.</p>
<p>But that wasn’t the last tweak. As time went on, people realized that the Earth’s journey wasn’t exactly 365.25 days – it <a href="https://airandspace.si.edu/stories/editorial/science-leap-year">actually took 365.24219 days</a>, which is about 11 minutes less. So adding a whole day every four years was actually a little more correction than was needed. </p>
<p>In 1582, Pope Gregory XIII signed an order that made a small adjustment. There would still be a leap year every four years, except in “century” years – years divisible by 100, like 1700 or 2100 – unless they were also divisible by 400. It might sound a bit like a puzzle, but this adjustment made the calendar <a href="https://airandspace.si.edu/stories/editorial/science-leap-year">even more accurate</a> – and from that point on, it was known as the Gregorian calendar.</p>
<h2>What if we didn’t have leap years?</h2>
<p>If the calendar didn’t make that small correction every four years, it would gradually fall out of alignment with the seasons. Over centuries, this could lead to the <a href="https://www.britannica.com/story/whats-the-difference-between-a-solstice-and-an-equinox">solstices and equinoxes</a> occurring at different times than expected. Winter weather might develop in what the calendar showed as summer, and farmers could become confused about when to plant their seeds.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/YTOr8_ILqGw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Without leap years, our calendar would gradually become disconnected from the seasons.</span></figcaption>
</figure>
<p>Other calendars around the world have their own ways of keeping time. The Jewish calendar, which is regulated by <a href="https://www.britannica.com/topic/Jewish-religious-year">both the Moon and the Sun</a>, is like a big puzzle with a 19-year cycle. Every now and then, it adds a leap month to make sure that special celebrations happen at just the right time. </p>
<p>The <a href="https://ing.org/resources/for-all-groups/calendar-of-important-islamic-dates/">Islamic calendar</a> is even more unusual. It follows the <a href="https://spaceplace.nasa.gov/moon-phases/en/">phases of the Moon</a> and doesn’t add extra days. Since a lunar year is only about 355 days long, key dates on the Islamic calendar move 10 to 11 days earlier each year on the solar calendar. </p>
<p>For example, Ramadan, the <a href="https://ing.org/resources/for-all-groups/calendar-of-important-islamic-dates/">Islamic month of fasting</a>, falls in the ninth month of the Islamic calendar. In 2024, it will run from March 11 to April 9; in 2025, it will occur from March 1-29; and in 2026, it will be celebrated from Feb. 18 to March 19.</p>
<h2>Learning from the planets</h2>
<p>Astronomy originated as a way to make sense of our daily lives, linking the events around us to celestial phenomena. The concept of leap years exemplifies how, from early ages, humans found order in conditions that seemed chaotic. </p>
<p>Simple, unsophisticated but effective tools, born from creative ideas of ancient astronomers and visionaries, provided the first glimpses into understanding the nature that envelops us. Some <a href="https://www.britannica.com/science/astronomy/History-of-astronomy">ancient methods</a>, such as <a href="https://sci.esa.int/web/gaia/-/53196-the-oldest-sky-maps">astrometry and lists of astronomical objects</a>, persist even today, revealing the timeless essence of our quest to understand nature. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photograph of an intricate schematic guide to the night sky." src="https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=356&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=356&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=356&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=447&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=447&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575719/original/file-20240214-30-of8z7y.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=447&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ancient Egyptians were dedicated astronomers. This section from the ceiling of the tomb of Senenmut, a high court official in Egypt, was drawn sometime circa 1479–1458 B.C.E. It shows constellations, protective gods and 24 segmented wheels for the hours of the day and the months of the year.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Senenmut-Grab.JPG">NebMaatRa/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>People who do research in physics and astronomy, the <a href="https://scholar.google.com/citations?user=t4L_D18AAAAJ&hl=en">field that I study</a>, are inherently curious about the workings of the universe and our origins. This work is exciting, and also extremely humbling; it constantly shows that in the grand scheme, our lives occupy a mere second in the vast expanse of space and time – even in leap years when we add that extra day.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/218330/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bhagya Subrayan does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Humans have synced their calendars to the sun and moon for centuries, but every so often, these systems need a little correction.Bhagya Subrayan, PhD Student in Physics and Astronomy, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2213992024-02-13T13:22:45Z2024-02-13T13:22:45ZWhy having human remains land on the Moon poses difficult questions for members of several religions<p>Sending human remains to the Moon on the first commercial lunar lander, Peregrine 1, on Jan. 8, 2024, <a href="https://www.scientificamerican.com/article/human-remains-are-headed-to-the-moon-despite-objections/">along with scientific instruments</a>, caused a controversy.</p>
<p>Buu Nygren, president of the Navajo Nation, objected, saying that “<a href="https://www.cnn.com/2024/01/05/world/peregrine-moon-mission-navajo-nation-objection-human-remains-scn/index.html">the moon holds a sacred place</a>” in Navajo and other tribal traditions and should not be defiled in this way. The inside of the lander was to be a kind of “<a href="https://elysiumspace.com/">space burial</a>” for remains of some 70 people. Each of the families had <a href="https://www.celestis.com/experiences-pricing/">paid over US$12,000 for a permanent memorial on the Moon</a>. </p>
<p>As <a href="https://www.holycross.edu/academics/programs/religious-studies/faculty/joanne-pierce">professors</a> <a href="https://www.holycross.edu/academics/programs/religious-studies/faculty/mathew-schmalz">of religious studies</a> who have taught courses on death rites, we know that death rituals in the world’s religions have been shaped by millennia of tradition and practice. While these ashes didn’t make it to the Moon because of a <a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=PEREGRN-1">propellant leak</a>, their presence on the lander raised some important religious issues: Beliefs about the polluting nature of the corpse, the acceptability of cremation and the sacredness of the Moon vary across traditions. </p>
<h2>Jewish death rituals and purification</h2>
<p>In ancient Judaism, certain activities were believed to be polluting, rendering a person unfit to participate in prayers and animal sacrifices offered exclusively at the Temple in Jerusalem. There were many ways in which one could become ritually unclean, and each level of pollution was cleansed by an appropriate purification rite. <a href="https://www.religiousrules.com/Judaismpurity03corpse.htm">Direct contact with a human corpse</a> was believed to cause the most intense form of pollution; even touching a person or object that had been in contact with a corpse would cause a lesser level of defilement.</p>
<p>After the Romans <a href="https://rpl.hds.harvard.edu/faq/destruction-second-temple-70-ce">destroyed the Temple in 70 C.E.</a>, Jewish religious practice changed dramatically, including rules about purification. These days, after a burial or visit to a cemetery, many Jewish people wash their hands to wash away negative <a href="https://outorah.org/p/64492/">spirits or energy</a>.</p>
<p>In Judaism, the bodies of the dead are to be buried or entombed in the earth. Cremation of human bodies, <a href="https://www.chabad.org/library/article_cdo/aid/510874/jewish/Why-Does-Judaism-Forbid-Cremation.htm">rejected for centuries</a>, has become more popular but <a href="https://www.myjewishlearning.com/article/judaism-on-cremation/">still remains a controversial option</a> due to the older tradition of respect for the body as a creation of God – to be buried intact and without mutilation.</p>
<h2>Christian death rituals over the centuries</h2>
<p>Before Christianity developed in the first century C.E., <a href="https://doi.org/10.1007/978-94-009-9497-3_1">Roman civil religion</a> stressed the need to separate the living from the dead. Corpses or cremated remains were interred in burial places outside cities and town – in <a href="https://www.laphamsquarterly.org/city/necropolis">the necropolis</a>, literally a city of the dead. As in Judaism, <a href="https://doi.org/10.4314/actat.v26i2.52569">any visitor needed purification</a> afterward. </p>
<p>As monotheists, Christians rejected belief in the Greek and Roman gods and goddesses, including the <a href="https://www.theoi.com/Titan/Selene.html#:%7E:text=SELE%E2%80%B2NE%20(Sel%C3%AAn%C3%AA)%2C,371%2C%20%">Moon goddess called Selene or Luna</a>. They also refused to participate in Roman state religious rituals or activities based on pagan polytheism. Decades later, after Christianity became the official imperial religion, Christians moved the <a href="http://csla.history.ox.ac.uk/record.php?recid=E01019">remains of people they considered holy into towns and cities</a> to be re-entombed for easier veneration inside churches.</p>
<p>During the medieval period, ordinary Christians desired to be buried close to these saints in anticipation of the resurrection of the body at the second coming of Christ. Graveyards around the church were <a href="https://www.cornellpress.cornell.edu/book/9781501753855/standing-on-holy-ground-in-the-middle-ages/">consecrated as “holy ground</a>.” In this way, Christians believed that the departed might continue to <a href="https://referenceworks.brillonline.com/entries/encyclopedia-of-medieval-pilgrimage/burial-ad-sanctos-SIM_00143#:%7E:text=Burial%20">benefit from the holiness of the saints</a>. Their bodies were considered sources of spiritual blessing rather than causes of spiritual pollution.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A relief showing a corpse being placed in a coffin as people stand around, one holding a tall crucifix." src="https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574710/original/file-20240209-26-yavs36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fourth-century Christian burial depicted in relief at the Shrine of San Vittore in Ciel d'Oro, Basilica of Sant'Ambrogio, Milan.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/2/23/9691_-_Milano_-_S._Ambrogio_-_San_Vittore_in_Ciel_d%27oro_-_Foto_Giovanni_Dall%27Orto_25-Apr-2007.jpg">G.dallorto, Attribution/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Increasingly today, cremation is considered acceptable, although the Catholic Church requires that cremated remains <a href="https://www.usccb.org/prayer-and-worship/sacraments-and-sacramentals/bereavement-and-funerals/cremation-and-funerals">must not be scattered or partitioned</a> but buried or placed elsewhere in cemeteries. </p>
<p>Unlike some other religions, neither Judaism nor Christianity considers the Moon divine or sacred. As part of God’s creation, it <a href="https://www.rmg.co.uk/stories/topics/when-easter#:%7E:text=The%20">plays a role</a> in setting the religious calendars. In both Jewish and Christian spiritual writing, the <a href="https://blog.nli.org.il/en/jewish_moon">Moon is used as a spiritual analogy</a>: in Judaism, of the majesty of God, and in Christianity, of Christ and the church.</p>
<h2>Islamic beliefs on burial</h2>
<p><a href="https://blogs.icrc.org/law-and-policy/2018/11/01/respect-for-the-dead-under-islamic-law-considerations-for-humanitarian-forensics/">Cremation is strictly prohibited in Islam</a>. After death, the deceased is <a href="https://www.islamicity.org/5586/preparation-of-te-deceased-and-janazah-prayers/">ritually washed, wrapped in shrouds</a> and brought for burial in a cemetery as soon as possible.</p>
<p>After a <a href="https://yaqeeninstitute.org/watch/series/ep-1-the-janazah-prayer-for-those-left-behind">funeral prayer</a>, led by an imam or senior member of the community, the deceased is buried – usually without a coffin – with their head oriented toward the holy city of Mecca. The soul of the deceased is <a href="https://zamzam.com/blog/life-after-death-in-islam/">said to visit their loved ones</a> on the seventh and 40th days after death. </p>
<p>The <a href="https://quran.com/en/fussilat/37">Quran warns against worshiping the Moon</a>, as was done in pre-Islamic culture, because worship is due to God alone.</p>
<p>In September 2007, when the first Muslim astronaut from Malaysia got ready to go into space, the Malaysian National Space Agency <a href="https://mg.co.za/article/2007-09-20-islamic-body-rules-on-how-to-pray-wash-die-in-space/">published religious directives</a> on burial rituals for Muslims in space. These directives said if bringing the body back wasn’t possible, then he would be “interred” in space after a brief ceremony. And if no water was available in space for the ceremonial rituals, then “holy dust” should be swept onto the face and hands “even if there is no dust” in the space station. </p>
<h2>Hindu and Buddhist funerary practices</h2>
<p>Hinduism is a diverse religion, and so funeral practices often vary according to culture and context. Most commonly, death and the period following a person’s death are associated with <a href="https://doi.org/10.1177/006996689023001007">ritual pollution</a>. Because of this, the deceased should be cremated within 24 hours after death.</p>
<p>The cremation of the corpse cuts the ties of the soul, or the <a href="https://www.britannica.com/topic/atman">atman</a>, to the body, allowing it to move on to the next level of existence and eventually be reincarnated. The ashes are collected and placed into an urn on the third day after cremation and immersed in a body of water, ideally a sacred river such as the Ganges.</p>
<p>Within Hinduism, the Moon has played an important role in conceptualizing what happens to the dead. For example, the ancient Hindu texts describe the spirits of the virtuous dead as entering Chandraloka, or the realm of the Moon, where they experience happiness for a time before being reincarnated.</p>
<p>In the many forms of Buddhism, death provides an opportunity for mourners to reflect <a href="https://tricycle.org/magazine/buddhist-death-rites/">on the impermanence of all things</a>. While in Tibetan Buddhism there is the tradition of “<a href="https://www.jstor.org/stable/29757283">sky burial</a>,” in which the deceased is dismembered and left to the elements, in most forms of Buddhism the dead are usually cremated and, as in Hinduism, the corpse is considered polluting beforehand. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A person lighting a candle at an altar, painted in red color, with white flowers in two vases and incense sticks in a small pot." src="https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574713/original/file-20240209-16-vrekcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A ritual being performed at a Thai funeral ceremony.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/funeral-watering-ceremony-thai-cultural-ritual-royalty-free-image/1831759719?phrase=buddhist+cremation&adppopup=true">Surasak Suwanmake/Moment via Getty Images</a></span>
</figcaption>
</figure>
<p>In older forms of Buddhism in Nepal and Tibet, the Moon was understood to be <a href="https://www.metmuseum.org/art/collection/search/38344#:%7E:text=Worship%20of%20the%20moon%20god">identified with the god Chandra</a>, who rides on a chariot. The Moon is also one of the nine astrological deities whose movement provides insight for reckoning individual and collective futures.</p>
<h2>Difficult questions</h2>
<p>In response to the Navajo objection that landing ashes on the Moon was a defilement, the CEO of Celestis, the company that paid for capsules containing the ashes, <a href="https://spacepolicyonline.com/news/biden-administration-to-consult-with-navajo-about-human-remains-on-the-moon/">issued a statement</a> stressing that launching containers of human ashes to the Moon is “the antithesis of desecration … it’s celebration.” </p>
<p>In the end, the question was moot. Peregrine 1 <a href="https://www.cnn.com/2024/01/15/world/peregrine-moon-lander-failure-nasa-scn/index.html">never made its soft landing on the Moon</a> because of an engine malfunction, and its <a href="https://www.bbc.com/news/science-environment-67962397">payload was destroyed</a> after entering the atmosphere. </p>
<p>As more people decide to send their ashes into space, however, religious conflicts are bound to arise. The key concern, and not just for the Navajo Nation, will be how to respect all religious traditions as humans explore and commercialize the Moon. It still remains a problem today here on Earth.</p><img src="https://counter.theconversation.com/content/221399/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Two scholars who study death rituals explain that the corpse is considered spiritually polluting in many religious traditions, while the Moon holds a sacred place.Joanne M. Pierce, Professor Emerita of Religious Studies, College of the Holy CrossMathew Schmalz, Professor of Religious Studies, College of the Holy CrossLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2208222024-02-07T13:12:35Z2024-02-07T13:12:35ZThe divine matchmaker in Chinese mythology − Old Man Under the Moon − who helps couples find love<figure><img src="https://images.theconversation.com/files/573555/original/file-20240205-21-5gjipi.jpg?ixlib=rb-1.1.0&rect=58%2C22%2C4806%2C3184&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Looking for love − a store in Huaian, in China's eastern Jiangsu province, selling flowers on Valentine's Day.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/vendor-prepares-flowers-for-sale-on-valentines-day-in-news-photo/1247125259?adppopup=true">STR/AFP via Getty Images</a></span></figcaption></figure><p>In China, people celebrate Valentine’s Day on Feb. 14, but there are at least three holidays and cultural traditions centered on romantic love. A figure that ties together these other holidays is the Old Man Under the Moon – Yuexia Laoren in Mandarin, or Yuelao for short – who is believed to be a <a href="https://www.lungshan.org.tw/tw/02_2_19_gods.php">divine matchmaker</a>. </p>
<p>In many cultures across the world, including China, <a href="https://archive.org/details/encyclopediaofsexandgendervolume3/page/n157/mode/2up">parents traditionally arranged their children’s marriages</a>, and love was not necessarily their main concern. In pre-modern China, daughters had little say over their marriage partners. Moreover, they were seen as belonging more to their future husbands’ families than to their birth families. Under these conditions, unmarried girls would <a href="https://www.simonandschuster.com/books/Food-and-Festivals-of-China/Yan-Liao/China-The-Emerging-Superpower/9781422294482">pray to the Old Man Under the Moon for a happy marriage</a>.</p>
<p>Girls could either make offerings at home or visit a temple where an image of the Old Man Under the Moon was enshrined. There are other figures in Chinese mythology, such as the “Weaving Maiden” and “Moon Goddess,” who are worshiped for good luck in love. But the Old Man Under the Moon is the most popular god of love and marriage. These days, the name Yuelao has even become a <a href="http://dx.doi.org/10.17507/tpls.0612.10">general term for “matchmaker</a>.” </p>
<p>As a <a href="https://faculty.utk.edu/Megan.Bryson">scholar of Chinese religious history</a>, I know that understandings of gods can change over time. These days, men and women pray to the Old Man Under the Moon to find their own love match, while the Rabbit God takes care of devotees looking for same-sex romance. </p>
<h2>The Old Man Under the Moon</h2>
<p>The Old Man Under the Moon was first mentioned in a ninth-century short story called “<a href="https://www.ucpress.edu/book/9780520081581/the-inner-quarters">Engagement Inn</a>,” where he arranged marriages as a divine official. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An icon of an old man with a long flowing beard, holding a long chord in one one hand and register in another." src="https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1271&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1271&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1271&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1597&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1597&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573556/original/file-20240205-19-c60osd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1597&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Old Man Under the Moon at Xiahai City God’s Temple in Dadaocheng, Taipei, Taiwan.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/4/47/%E5%A4%A7%E7%A8%BB%E5%9F%95%E9%9C%9E%E6%B5%B7%E5%9F%8E%E9%9A%8D%E5%BB%9F%E6%9C%88%E4%B8%8B%E8%80%81%E4%BA%BA.jpg">Sean Chiu via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>In the story, an unmarried man named Wei Gu set out before sunrise to meet a matchmaker. He saw an old man reading a document by moonlight and tried to get a peek, but found that he could not decipher the script. The old man laughed and told Wei Gu that he was a divine bureaucrat in charge of human marriages, and his document was a marriage register written in an otherworldly script. </p>
<p>Wei Gu then asked about his own prospects, to which the old man replied that Wei Gu would get married, but it would take 14 years. Wei Gu then asked about a bag the old man was holding. The old man pulled a red cord out of the bag and explained that he used those to tie the feet of a future couple so that fate would bring them together.</p>
<p>In the centuries that followed, the Old Man Under the Moon became an increasingly popular figure in Chinese literature, drama and religion. His statue was enshrined in temples, where unmarried people and their relatives could pray and make offerings in the hope of finding a match.</p>
<p>Like other divine bureaucrats in charge of human affairs, the Old Man Under the Moon is rarely a temple’s central deity, but his icon appears in side halls alongside deities in charge of fertility and education. </p>
<p>Fittingly, he looks like an old man with a long white beard, and he holds the red cords that bind couples to each other. People looking to find a partner often leave red strings tied to tree branches, sometimes with short prayer texts attached to the strings, outside shrines to Old Man Under the Moon. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Red strings and prayer texts tied around a tree outside a shrine to the Old Man Under the Moon in Yunnan, China." src="https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573340/original/file-20240205-17-oc7yd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Those looking for love will pray to the Old Man Under the Moon and tie red threads.</span>
<span class="attribution"><span class="source">Megan Bryson</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Heavenly romance</h2>
<p>The Old Man Under the Moon can be worshiped year-round, but he has special ties to two holidays in the traditional Chinese calendar: the Double Seventh Festival and the Moon Festival. Valentine’s Day is a new addition to existing Chinese holidays celebrating love and marriage. </p>
<p>In Chinese culture, the most important holiday for romance is the Double Seventh Festival, which appropriately falls on the seventh day of the seventh lunar month. This festival commemorates the story of the star-crossed lovers <a href="https://search.proquest.com/openview/9c442d8613959f71c8340a3a8407530f/1?pq-origsite=gscholar&cbl=18750&diss=y">Weaving Maiden and Cowherd</a>, who live on separate constellations and can meet only once a year.</p>
<p>Unmarried girls make offerings to the Weaving Maiden in hopes of finding a good husband, in addition to saying prayers to Old Man. According to Taiwanese tradition, on the Double Seventh Festival, the Weaving Maiden <a href="https://historic.tainan.gov.tw/index.php?option=module&lang=cht&task=pageinfo&id=957&index=7">compiles a list of all unmarried men and women</a> to give to the Old Man Under the Moon. The Old Man then pairs up the single men and women in his marriage registry, binding their feet to seal their shared fate. </p>
<p>The Mid-Autumn Festival, or Moon Festival, on the 15th day of the eighth lunar month focuses on family togetherness, but it also includes <a href="https://www.nlb.gov.sg/main/article-detail?cmsuuid=9907c553-19b3-4168-a613-49d35f2893ae">romantic themes</a>. Unmarried girls traditionally <a href="https://www.simonandschuster.com/books/Food-and-Festivals-of-China/Yan-Liao/China-The-Emerging-Superpower/9781422294482">pray to the Moon Goddess Chang’e</a> and to the divine matchmaker Old Man Under the Moon for a good husband. The Moon Festival is seen as the <a href="https://www.lungshan.org.tw/tw/04_activity2.php?p=150&page=0">birthday</a> of the Old Man Under the Moon, so temples sometimes have special events in his honor. The moon represents both wholeness and romance, making it a fitting symbol for the divine matchmaker.</p>
<p>Even the most important holiday on the Chinese calendar, Lunar New Year, can be a time to <a href="https://www.womenshealthmag.com/tw/mental/relationship/g38893042/pray-to-yue-lao-you-need-to-know/">worship the Old Man Under the Moon</a>. As celebrants set their intentions and goals for the new year, those looking for love and marriage will make a point of sending prayers to the Old Man Under the Moon. </p>
<h2>The Rabbit God</h2>
<p>Apart from the Old Man Under the Moon, another divine matchmaker in Chinese mythology is the Rabbit God, who has been worshiped <a href="https://www.proquest.com/scholarly-journals/cult-hu-tianbao-eighteenth-century-discourse/docview/1308083280/se-2">as far back as the 18th century</a> as a god of love between men. </p>
<p>Members of the LGBTQ+ community in Taiwan revived the worship of this deity as a <a href="https://youtu.be/8iyBiV4ixW0?si=AWyDCjDrOiuLSpI7">same-sex counterpart</a> to the Old Man Under the Moon. The Rabbit God binds same-sex couples, just as the Old Man Under the Moon binds couples of the opposite sex.</p>
<p>Same-sex couples in Taiwan can visit <a href="https://www.weimingtang.org/index.php">Wei Ming Tang temple</a>, which is dedicated to the Rabbit God, to seek lasting romantic love and marriage. Worship of the Rabbit God can be done more openly in Taiwan, which is the only place in Asia where <a href="https://www.cnn.com/2019/05/17/asia/taiwan-same-sex-marriage-intl/index.html">same-sex marriage is legal</a>. LGBTQ+ relationships are frowned upon in mainland China.</p>
<p>The Old Man Under the Moon has long sustained the hope for romance and love in arranged marriages. Now that most people in Chinese culture find their own marriage partners, he offers hope that people will be able to find their match in a sea of possibilities. The Rabbit God offers the same hope for the LGBTQ+ community, especially in Taiwan.</p><img src="https://counter.theconversation.com/content/220822/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Megan Bryson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Young people in China are no longer settling into marriages arranged by their parents. But they are still looking for blessings from Chinese gods to find everlasting love.Megan Bryson, Associate Professor of Religious Studies, University of TennesseeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2198922024-02-05T13:30:46Z2024-02-05T13:30:46ZUS Moon landing marks new active phase of lunar science, with commercial launches of landers that will study solar wind and peer into the universe’s dark ages<figure><img src="https://images.theconversation.com/files/567940/original/file-20240104-21-s3p58r.jpg?ixlib=rb-1.1.0&rect=4%2C17%2C2991%2C1868&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The dark, far side of the Moon is the perfect place to conduct radio astronomy. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/LunarEclipse/704e3da2df90473486270e23aa73419d/photo?Query=moon&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=399&digitizationType=Digitized&currentItemNo=12&vs=true&vs=true">AP Photo/Rick Bowmer</a></span></figcaption></figure><p>For the first time since 1972, NASA <a href="https://www.intuitivemachines.com/im-1">landed a craft on the surface of the Moon</a> in February 2024. But the agency didn’t do it alone – instead, it partnered with commercial companies. Thanks to new technologies and <a href="https://www.nasa.gov/commercial-lunar-payload-services/">public-private partnerships</a>, the scientific projects brought to the Moon on this craft and on future missions like it will open up new realms of scientific possibility. </p>
<p>As parts of several projects launching this year, teams of scientists, including myself, will conduct radio astronomy from the south pole and the far side of the Moon.</p>
<p>NASA’s <a href="https://www.nasa.gov/commercial-lunar-payload-services/">commercial lunar payload services program</a>, or CLPS, will use uncrewed landers to conduct NASA’s first science experiments from the Moon in over 50 years. The CLPS program differs from past space programs. Rather than NASA building the landers and operating the program, commercial companies will do so in a public-private partnership. NASA identified <a href="https://www.nasa.gov/commercial-lunar-payload-services/clps-providers/">about a dozen companies</a> to serve as vendors for landers that will go to the Moon. </p>
<figure>
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<figcaption><span class="caption">CLPS will send science payloads to the Moon in conjunction with the Artemis program’s crewed missions.</span></figcaption>
</figure>
<p>NASA buys space on these landers for <a href="https://science.nasa.gov/lunar-science/clps-deliveries/">science payloads</a> to fly to the Moon, and the companies design, build and insure the landers, as well as contract with rocket companies for the launches. Unlike in the past, NASA is one of the customers and not the sole driver. </p>
<h2>Peregrine and Odysseus, the first CLPS landers</h2>
<p>The first two CLPS payloads are scheduled to launch during the first two months of 2024. There’s the <a href="https://science.nasa.gov/lunar-science/clps-deliveries/to2-astrobotic/">Astrobotics payload</a>, which launched Jan. 8 before its lander, named Peregrine, <a href="https://www.space.com/astrobotic-peregrine-moon-lander-headed-to-earth">experienced a fuel issue</a> that cut its journey to the Moon short. </p>
<p>Next, there’s the <a href="https://science.nasa.gov/lunar-science/clps-deliveries/op-to2-intuitive-machines/">Intuitive Machines payload</a>. Intuitive Machines’ lander, named Odysseus, <a href="https://www.intuitivemachines.com/im-1">landed near the south pole of the Moon</a> on Feb. 22, 2024. NASA has also planned a <a href="https://science.nasa.gov/lunar-science/clps-deliveries/">few additional landings</a> – about two or three per year – for each of the next few years.</p>
<p>I’m a <a href="https://www.colorado.edu/faculty/burns/">radio astronomer</a> and co-investigator on NASA’s <a href="https://www.colorado.edu/ness/projects/radiowave-observations-lunar-surface-photoelectron-sheath-rolses">ROLSES program</a>, otherwise known as Radiowave Observations at the Lunar Surface of the photoElectron Sheath. ROLSES was built by the NASA Goddard Space Flight Center and is led by <a href="https://science.gsfc.nasa.gov/sci/bio/natchimuthuk.gopalswamy-1">Natchimuthuk Gopalswamy</a>. </p>
<p>The ROLSES instrument landed on the Moon as <a href="https://www.intuitivemachines.com/_files/ugd/7c27f7_51f84ee63ea744a9b7312d17fefa9606.pdf">one of six NASA payloads</a> on the Intuitive Machines lander in February. Between ROLSES and another mission scheduled for the lunar far side in two years, LuSEE-Night, our teams will land NASA’s first two radio telescopes on the Moon by 2026. </p>
<h2>Radio telescopes on the Moon</h2>
<p>The Moon – particularly the far side of the Moon – is an ideal place to do radio astronomy and study signals from extraterrestrial objects such as the Sun and the Milky Way galaxy. On Earth, the ionosphere, which <a href="https://theconversation.com/earths-magnetic-field-protects-life-on-earth-from-radiation-but-it-can-move-and-the-magnetic-poles-can-even-flip-216231">contains Earth’s magnetic field</a>, distorts and absorbs radio signals below the <a href="https://www.fcc.gov/general/fm-radio">FM band</a>. These signals might get scrambled or may not even make it to the surface of the Earth.</p>
<p>On Earth, there are also TV signals, satellite broadcasts and defense radar systems <a href="https://theconversation.com/radio-interference-from-satellites-is-threatening-astronomy-a-proposed-zone-for-testing-new-technologies-could-head-off-the-problem-199353">making noise</a>. To do higher sensitivity observations, you have to go into space, away from Earth. </p>
<p>The Moon is what scientists call <a href="https://www.sciencefocus.com/space/what-is-tidal-locking">tidally locked</a>. One side of the Moon is always facing the Earth – the “<a href="https://www.rmg.co.uk/stories/topics/what-man-moon">man in the Moon</a>” side – and the other side, <a href="https://theconversation.com/whats-on-the-far-side-of-the-moon-111306">the far side</a>, always faces away from the Earth. The Moon has no ionosphere, and with about 2,000 miles of rock between the Earth and the far side of the Moon, there’s no interference. It’s radio quiet. </p>
<p>For our first mission with ROLSES, which launched in February 2024, we will collect data about environmental conditions on the Moon near its south pole. On the Moon’s surface, <a href="https://theconversation.com/solar-storms-can-destroy-satellites-with-ease-a-space-weather-expert-explains-the-science-177510">solar wind</a> directly strikes the lunar surface and creates a charged gas, called <a href="https://www.psfc.mit.edu/vision/what_is_plasma">a plasma</a>. Electrons lift off the negatively charged surface to form a highly ionized gas. </p>
<p>This doesn’t happen on Earth because <a href="https://theconversation.com/earths-magnetic-field-protects-life-on-earth-from-radiation-but-it-can-move-and-the-magnetic-poles-can-even-flip-216231">the magnetic field deflects</a> the solar wind. But there’s no global magnetic field on the Moon. With a low frequency radio telescope like ROLSES, we’ll be able to measure that plasma for the first time, which could help scientists figure out how to keep astronauts safe on the Moon. </p>
<p>When astronauts walk around on the surface of the Moon, they’ll pick up different charges. It’s like walking across the carpet with your socks on – when you reach for a doorknob, a spark can come out of your finger. The same kind of discharge happens on the Moon from the charged gas, but it’s potentially more harmful to astronauts. </p>
<h2>Solar and exoplanet radio emissions</h2>
<p>Our team is also going to use ROLSES to look at the Sun. The Sun’s surface releases shock waves that send out highly energetic particles and low radio frequency emissions. We’ll use the radio telescopes to measure these emissions and to see bursts of low-frequency radio waves from shock waves within the solar wind.</p>
<p>We’re also going to examine the Earth from the surface of the Moon and use that process as a template for <a href="https://theconversation.com/nasas-tess-spacecraft-is-finding-hundreds-of-exoplanets-and-is-poised-to-find-thousands-more-122104">looking at radio emissions from exoplanets</a> that may harbor life <a href="https://theconversation.com/are-there-any-planets-outside-of-our-solar-system-164062">in other star systems</a>. </p>
<p>Magnetic fields are important for life because they shield the planet’s surface from the <a href="https://theconversation.com/the-scorching-winds-on-the-surface-of-the-sun-and-how-were-forecasting-them-44098">solar/stellar wind</a>. </p>
<p>In the future, our team hopes to use specialized arrays of antennas on the far side of the Moon to observe nearby stellar systems that are known to have exoplanets. If we detect the same kind of radio emissions that come from Earth, this will tell us that the planet has a magnetic field. And we can measure the strength of the magnetic field to figure out whether it’s strong enough to shield life.</p>
<h2>Cosmology on the Moon</h2>
<p>The Lunar Surface Electromagnetic Experiment at Night, or <a href="https://www.colorado.edu/ness/projects/lunar-surface-electromagnetics-experiment-night-lusee-night">LuSEE-Night</a>, will fly in early 2026 to the far side of the Moon. LuSEE-Night marks scientists’ first attempt to do cosmology on the Moon.</p>
<p>LuSEE-Night is a novel collaboration between NASA and the Department of Energy. Data will be sent back to Earth using a communications satellite in lunar orbit, <a href="https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/A_pathway_for_communicating_at_the_Moon">Lunar Pathfinder</a>, which is funded by the European Space Agency.</p>
<p>Since the far side of the Moon is <a href="https://cosmicdawn.astro.ucla.edu/lunar_telescopes.html">uniquely radio quiet</a>, it’s the best place to do cosmological observations. During the two weeks of lunar night that happen every 14 days, there’s no emission coming from the Sun, and there’s no ionosphere. </p>
<p>We hope to study an unexplored part of the early universe called the <a href="https://www.astronomy.com/science/the-beginning-to-the-end-of-the-universe-the-cosmic-dark-ages/">dark ages</a>. The dark ages refer to before and just after the formation of the very first stars and galaxies in the universe, which is beyond what the <a href="https://webb.nasa.gov/">James Webb Space Telescope</a> can study.</p>
<p>During the dark ages, the universe was less than 100 million years old – today the universe is 13.7 billion years old. The universe was full of hydrogen <a href="https://theconversation.com/after-our-universes-cosmic-dawn-what-happened-to-all-its-original-hydrogen-65527">during the dark ages</a>. That hydrogen radiates through the universe at low radio frequencies, and when new stars turn on, they ionize the hydrogen, producing a radio signature in the spectrum. Our team hopes to measure that signal and learn about how the earliest stars and galaxies in the universe formed.</p>
<p>There’s also a lot of potential new physics that we can study in this last unexplored cosmological epoch in the universe. We will investigate the nature of <a href="https://theconversation.com/dark-matter-the-mystery-substance-physics-still-cant-identify-that-makes-up-the-majority-of-our-universe-85808">dark matter</a> and early <a href="https://theconversation.com/explainer-the-mysterious-dark-energy-that-speeds-the-universes-rate-of-expansion-40224">dark energy</a> and test our fundamental models of physics and cosmology in an unexplored age.</p>
<p>That process is going to start in 2026 with the LuSEE-Night mission, which is both a fundamental physics experiment and a cosmology experiment.</p>
<p><em>This is an updated version of an article originally published on Feb. 5, 2024.</em></p><img src="https://counter.theconversation.com/content/219892/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jack Burns receives funding from NASA.</span></em></p>Projects under NASA’s CLPS program – including the Odysseus lander that made it to the lunar surface – will probe unexplored questions about the universe’s formation.Jack Burns, Professor of Astrophysical and Planetary Sciences, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2212922024-02-04T13:33:52Z2024-02-04T13:33:52ZWhy now is the time to address humanity’s impact on the moon<figure><img src="https://images.theconversation.com/files/572329/original/file-20240131-15-x809b1.jpg?ixlib=rb-1.1.0&rect=0%2C29%2C6500%2C3532&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mining the moon for its resources is growing more and more likely.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Humans have always looked at the sky, using the stars as navigation guides or for spiritual storytelling. Every human civilization has looked to the stars and used celestial movements to measure time and find meaning.</p>
<p>This insatiable thirst for knowledge combined with technological advancements have made it possible for us to dream of travelling in space. These dreams became more and more real after the Second World War, the Industrial Revolution, the Cold War and the large-scale exploitation of the Earth’s resources.</p>
<p>Dreams of space travel started small with the <a href="https://www.nasa.gov/image-article/sputnik-1/">launch of Sputnik-1 by the Soviet Union</a>, and escalated with the <a href="https://www.nasa.gov/history/apollo-11-mission-overview/">U.S. Apollo landing on the moon in 1969</a>.</p>
<p>Six decades later, plans are ramping up for <a href="https://www.virgingalactic.com/">space tourism</a>, <a href="https://www.nasa.gov/specials/artemis/">missions to the moon and Mars</a>, and <a href="https://www.space.com/moon-mining-gains-momentum">mining on the moon</a>. </p>
<p>The <a href="https://lunarresourcesregistry.com/">Lunar Resources Registry</a>, a private business that locates valuable resources on the moon and helps investors conduct the required exploration and extraction operations, notes: “The space race is evolving into space industrialization.” </p>
<p>According to NASA, “the moon holds <a href="https://www.jpl.nasa.gov/infographics/the-lunar-gold-rush-how-moon-mining-could-work">hundreds of billions of dollars of untapped resources</a>,” including water, helium-3 and <a href="https://geology.com/articles/rare-earth-elements/">rare earth metals</a> used in electronics.</p>
<h2>The dawn of the Anthropocene</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a black and white photo of a footprint on a sedimentary surface" src="https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=608&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=608&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=608&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=764&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=764&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572349/original/file-20240131-21-a3nhp0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=764&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A close-up view of an astronaut’s footprint in the lunar soil, photographed in July 1969.</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/details/6901250">(Marshall Space Flight Center/NASA)</a></span>
</figcaption>
</figure>
<p>As a group of academics researching various aspects of environmental sustainability on Earth, we are alarmed at the speed of these developments and the impacts resource exploitation will have on lunar and space environments. </p>
<p>There is a movement among the international geologic scientific community calling for a new epoch — <a href="https://brocku.ca/and/crawford-lake/">the Anthropocene</a> — reflecting the enormous extent to which human activity has altered the planet since the end of the Second World War.</p>
<p>Stratigraphers — geologists who study the layers of rock and sediment — look for measurable global impact of human activities in the geologic record. According to their research, the starting point for the Anthropocene has been identified as beginning in the 1950s, <a href="https://education.nationalgeographic.org/resource/anthropocene/">and the fallout from nuclear testing</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-term-anthropocene-jumped-from-geoscience-to-hashtags-before-most-of-us-knew-what-it-meant-130130">How the term 'Anthropocene' jumped from geoscience to hashtags – before most of us knew what it meant</a>
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<p>To shock humankind into preventing the extensive destruction in space that we have wrought on Earth, it may be effective to add a “<a href="https://doi.org/10.1038/s41561-023-01347-4">lunar Anthropocene</a>” to the moon’s geologic time scale.</p>
<p>The case for a lunar Anthropocene is interesting. It can be argued that since the first human contact with the moon’s surface, we have seen anthropogenic impact. This impact is likely to increase dramatically. This is presented as justification for a new geologic epoch for the moon. </p>
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<a href="https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a mushroom cloud caused by a nuclear explosion" src="https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=473&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=473&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=473&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=595&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=595&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572350/original/file-20240131-19-c72v6r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=595&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An image captured immediately after the first atomic explosion in Alamogordo, N.M., on July 16, 1945. The presence of nuclear traces of the fallout from the initial nuclear explosions is claimed to mark the beginning of the Anthropocene.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Damaging the Earth</h2>
<p>This new “human epoch” is hotly debated among stratigraphers as well as researchers in other disciplines. For humanities researchers and artists, the importance of the Anthropocene lies in the power the concept has to evoke human responsibility for bringing the Earth’s system to a <a href="https://www.esa.int/Applications/Observing_the_Earth/Space_for_our_climate/Understanding_climate_tipping_points">tipping point</a>. </p>
<p>In <a href="https://www.versobooks.com/en-ca/products/136-the-shock-of-the-anthropocene"><em>The Shock of the Anthropocene</em></a>, historians Christophe Bonneuil and Jean-Baptiste Fressoz argue that the new human epoch entails recognizing that technoscientific advances — which have driven socio-political economies relying on extractivism, consumption and waste — have led to the extent of damage we measure on Earth at present. </p>
<p>For millenia, most societies understood the importance of their relationship with the natural world for survival. But industrialization and the endlessly growing economy in developed countries has destroyed this relationship. </p>
<p>For example, trees used to be respected for providing timber, food, shade and more. But our industrial growth changed all that; in the past 100 years, <a href="https://ourworldindata.org/world-lost-one-third-forests">more trees have been cut</a> than had been felled in the preceding 9,000 years.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/killing-trees-how-true-environmental-protection-requires-a-revolution-in-how-we-talk-about-and-with-our-forests-214899">'Killing' trees: How true environmental protection requires a revolution in how we talk about, and with, our forests</a>
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</em>
</p>
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<h2>A lunar Anthropocene</h2>
<p>And now the Anthropocene, this age of human impact, is also arriving on the moon.</p>
<p>NASA estimates there are already <a href="https://www.ajc.com/news/national/500-000-pounds-human-trash-litters-the-moon-report-finds/wWeCaVjLmtz0u2ZunyqcLI/">227,000 kilos of human garbage littering the moon</a>, mostly from space explorations, including <a href="https://www.rmg.co.uk/stories/topics/strange-things-humans-have-left-on-moon">moon buggies and other equipment</a>, excrement, statues, golf balls, human ashes and flags, among other objects. </p>
<p>An increasing number of moon missions and extracting resources from the moon <a href="https://www.theguardian.com/science/2024/jan/06/moons-resources-could-be-destroyed-by-thoughtless-exploitation-nasa-warned">could destroy lunar environments</a>. This mirrors what has happened on our planet: humans have used this collection of “natural resources” and produced enough waste and degradation to bring us to the current <a href="https://www.earth.com/earthpedia-articles/its-too-late-the-6th-mass-extinction-is-here/">sixth mass extinction precipice</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/_tdsia6EZY8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">With the Artemis missions, NASA is planning to reestablish a human presence on the moon.</span></figcaption>
</figure>
<p>Our throwaway society leads to not only habitat destruction on Earth, but also now on the moon and in space. We must rethink what we really need. Without a fully functional Earth system, including biodiversity and nature’s contribution to life, we will be unable to survive. </p>
<p>If the intent is to issue a word of caution and pre-emptively shock and elicit a feeling of responsibility on the part of those actors likely to impact the moon’s surface, it may very well be the right time to name a lunar Anthropocene. This may help prevent the kind of extensive and careless destruction we have caused and continue to witness on Earth.</p><img src="https://counter.theconversation.com/content/221292/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christine Daigle receives funding from the Social Sciences and Humanities Research Council. </span></em></p><p class="fine-print"><em><span>Liette Vasseur receives funding from the Exploration New Frontiers Research Funds.</span></em></p><p class="fine-print"><em><span>Jennifer Ellen Good does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As space travel and lunar exploration becomes a near-future reality, we should consider the impact of human activities on the lunar environment.Christine Daigle, Professor of Philosophy, Brock UniversityJennifer Ellen Good, Associate Professor and Chair, Communication, Popular Culture and Film, Brock UniversityLiette Vasseur, Professor, Biological Sciences, Brock UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2221732024-01-29T16:38:10Z2024-01-29T16:38:10ZNasa’s Mars helicopter Ingenuity has ended its mission – its success paves the way for more flying vehicles on other planets and moons<figure><img src="https://images.theconversation.com/files/571847/original/file-20240129-15-v0glwl.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2270%2C1360&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Ingenuity helicopter on Mars.</span> <span class="attribution"><a class="source" href="https://mars.nasa.gov/resources/27421/ingenuity-at-two-years-on-mars/">NASA/JPL-Caltech/ASU/MSSS</a></span></figcaption></figure><p>It is difficult to emphasise the significance of the milestone surpassed by Nasa’s Mars helicopter, Ingenuity. </p>
<p>The little (1.8kg) helicopter <a href="https://mars.nasa.gov/resources/25608/nasas-perseverance-rover-lands-successfully-on-mars/">touched down with the Perseverance rover in 2021</a>. On 25 January, Nasa announced that the flying vehicle <a href="https://www.nasa.gov/news-release/after-three-years-on-mars-nasas-ingenuity-helicopter-mission-ends/">had to perform an emergency landing</a> which damaged one of its rotors and ended its mission. </p>
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<p>This reminds us that space exploration is still difficult to do. But Ingenuity’s three years on Mars proved that powered, controlled flight on Mars was possible. </p>
<p>The little helicopter lasted for far longer than had been planned and flew higher and further than many had envisaged. Beyond this Martian experiment, the rotorcraft’s success paves the way for other missions using flying vehicles to explore planets and moons.</p>
<p>The first landings on the Moon were static. The year 1969 was probably the most important one for space exploration, when <a href="https://www.nasa.gov/mission/apollo-11/">Apollo 11</a> and <a href="https://www.nasa.gov/mission/apollo-12/">Apollo 12</a> brought astronauts to the lunar surface, but 1970 was the year for planetary exploration. </p>
<p>In 1970, we had the <a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-060A">first soft landing on another planet</a>, Venus. The first robotic sample delivered to Earth from the Moon. And the first robot rover to drive around another body (also the Moon). </p>
<p>Since then, following over 50 years of planetary exploration and technology development, there have only been a small number of successful surface missions, and even fewer were able to move. Venus was visited by a dozen static landers between 1970 and 1985, and never again. </p>
<h2>From rovers to helicopters</h2>
<p>Mars was only successfully landed on three times between 1971 and 1976 before the <a href="https://mars.nasa.gov/mars-exploration/missions/pathfinder/">Pathfinder lander</a> and Sojourner rover arrived in 1997. The European Huygens spacecraft then landed on Titan, the moon of Saturn, in 2005. </p>
<p>These attempts at reaching the surface are rare, extremely difficult, and, historically, the landers were hardly ever mobile. Yet the Nasa <a href="https://mars.nasa.gov/mer/mission/overview/">Mars rovers Spirit, Opportunity</a>, <a href="https://mars.nasa.gov/msl/home/">Curiosity</a>, and <a href="https://mars.nasa.gov/mars2020/">Perseverance</a> have all exceeded their designs and travelled further and further.</p>
<p>And Ingenuity flew.</p>
<p>It wasn’t the first spacecraft to fly. Those would be the balloons deployed by the <a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1984-128F">Soviet Vega 1 and 2 missions</a>, which floated over Venus in 1985. But Ingenuity had control, cameras, and connectivity. It took photos of its rover and of Mars from an entirely new perspective. It commanded the world’s attention and captured our hearts.</p>
<p>In Moscow, I had the chance to see models and replicas of the Vega balloons and the first lunar rover. They made a stronger impression on me than the Mars rover twins being used at Nasa’s Jet Propulsion Laboratory (JPL) in California. The Soviet missions were more audacious and different, and they were from generations ago, before my time and long before my career as a planetary scientist.</p>
<p>Ingenuity was audacious, original and completely new. The photos it took, of Perseverance, finding technology discarded from the descent module that carried it down to Mars and of the Martian vistas from a bird’s eye view, were breathtaking. Meanwhile, Perseverance also took videos of Ingenuity flying in the air. Nothing like it had ever seen before.</p>
<figure class="align-center ">
<img alt="CGI image of a silver drone with eight propellers over the Martian surface" src="https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=380&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=380&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=380&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=478&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=478&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571881/original/file-20240129-23-b4r2m2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=478&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">An artist’s impression of the Dragonfly spacecraft in flight.</span>
<span class="attribution"><a class="source" href="https://dragonfly.jhuapl.edu/Gallery/">NASA/Johns Hopkins APL/Steve Gribben</a></span>
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<h2>Future flights</h2>
<p>Ingenuity had a rough ride getting there, however. The entire Mars 2020 mission (of Perseverance, Ingenuity and their transport systems) was sudden. </p>
<p>Following Nasa’s withdrawal from the joint European Space Agency ExoMars programme, which included a Mars rover mission, the US space agency started developing one on its own. This rover, later named Perseverance, went from announcement to concept to development and launch in just seven-and-a-half years.</p>
<p>And Ingenuity wasn’t included onboard at first. As an idea, it was proposed late in the development phase of Mars 2020, and faced serious opposition. It added extra complexity, cost, risk and new failure modes. It was also driven by an engineering objective, with the possibility of a little outreach – the opportunity to communicate the mission’s science and engineering to the public – on the side.</p>
<p>Ingenuity wasn’t intended to last for very long. It was designed to prove helicopter flight in the thin Mars atmosphere. It targeted five short flights over a month. Possible outcomes included hard landings, toppling over, losing power if its solar panels were covered in dust, or losing communication when it was far from the rover (this happened several times). </p>
<figure class="align-center ">
<img alt="Large silver balloon being launched in the desert." src="https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571874/original/file-20240129-25-1d0l8.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Aerial robotic balloons, or aerobots, like this Nasa prototype, could one day explore Venus.</span>
<span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/news/jpls-venus-aerial-robotic-balloon-prototype-aces-test-flights">Nasa / JPL-Caltech</a></span>
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<p>But it went way beyond expectations, surviving three years on the Martian surface, even through a dusty season, and making 72 flights. Much of its success was aided by the communication network that now exists at Mars. </p>
<p>Ingenuity receives instructions and transmits data to Perseverance, which communicates with a fleet of satellites that include the European ExoMars Trace Gas Orbiter, Nasa’s Maven spacecraft, and the Mars Reconnaissance Orbiter. These, in turn, communicate with two deep space networks on Earth, systems of radio antennas around the world that command and track spacecraft. </p>
<p>It took 50 years of planetary exploration to get here, but already we can see the impact on future exploration that Ingenuity’s mission is having. The next interplanetary rotorcraft will be the <a href="https://dragonfly.jhuapl.edu/">Dragonfly mission to Saturn’s moon Titan</a>. </p>
<p>It will be a very different from Ingenuity. It will weigh about a ton and fly with eight rotors. It is a huge vehicle designed to fly in Titan’s thick atmosphere. </p>
<p>One of the next Red Planet missions will be Mars Sample Return, aiming to collect sample containers of Martian soil being prepared and cached by Perseverance. This has been planned to be carried out with use of a rover, but the success of Ingenuity has led to the idea – and now the development – of <a href="https://mars.nasa.gov/msr/spacecraft/sample-recovery-helicopters/">a helicopter</a> to do that. </p>
<p>The future that Ingenuity has opened up for us is exciting. We’ll see helicopters on Mars and Venus, more balloons on Venus, swimming vehicles under the icy moons of Jupiter and Saturn, and maybe even an aeroplane or two.</p><img src="https://counter.theconversation.com/content/222173/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Olsen in an employee of the University of Oxford and receives funding from the UK Space Agency in support of Mars science.</span></em></p>Among the missions being planned is a huge helicopter drone to explore Saturn’s moon Titan.Kevin Olsen, UKSA Mars Science Fellow, Department of Physics, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2219962024-01-26T18:09:56Z2024-01-26T18:09:56ZHumans are going back to the Moon to stay, but when that will be is becoming less clear<figure><img src="https://images.theconversation.com/files/571678/original/file-20240126-28-5py8a0.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C2038%2C1532&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/nasa2explore/52547251628/in/album-72177720303788800/">NASA</a></span></figcaption></figure><p>A 2019 Time magazine <a href="https://timecoverstore.com/featured/the-next-space-race-time.html">cover portrayed</a> four astronauts running towards the Moon. Pictured alongside the headline “The Next Space Race”, one of the astronauts carried an American flag, one carried a Chinese flag and the other two belonged to space companies owned by billionaires: Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin. </p>
<p>Until recently, it seemed as if the US and SpaceX were set to win this race to return to the Moon with Nasa’s <a href="https://www.nasa.gov/specials/artemis/">Artemis programme</a>. But a number of setbacks have called that into question. And Blue Origin, China and other countries and companies are continuing their own lunar efforts.</p>
<p>On January 9 2024, Nasa announced that it was delaying the Artemis 2 mission, the first crewed flight of the <a href="https://www.nasa.gov/humans-in-space/space-launch-system/">Space Launch System (SLS)</a> and the Orion capsule – the vehicles built to send astronauts back to deep space. The flight would slip from late 2024 to no earlier than September 2025. This was due to some safety issues that need to be fixed on Orion. </p>
<p>Consequently, Artemis 3, which is supposed to involve the first crewed lunar landing since 1972, will take place no earlier than September 2026. Artemis 3 is to use <a href="https://www.spacex.com/vehicles/starship/">SpaceX’s Starship orbiter</a> as the lander for two crew members. This mission is set to put the first woman and the first person of colour on the lunar surface. </p>
<p>A non-American crew member could also walk on the Moon by 2030, highlighting the fact that Nasa has involved international partners in the Artemis venture. Up until now, <a href="https://www.space.com/how-many-people-have-walked-on-the-moon">just 12 humans have set foot on the Moon</a>. All of them have been male and all have been American.</p>
<figure class="align-center ">
<img alt="Astronauts study Moon's surface with various vehicles in the background" src="https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&rect=1%2C1%2C1020%2C573&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571507/original/file-20240125-19-6htotg.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">An artist’s rendering of US astronauts exploring the Moon.</span>
<span class="attribution"><span class="source">NASA</span></span>
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<p>However, the Starship orbiter, crucial to these aims, has experienced problems. A <a href="https://www.space.com/spacex-starship-second-test-flight-launch-explodes">second test launch</a> for the rocketship-like orbiter atop its huge booster rocket back in November 2023, was spectacularly destroyed eight minutes and six seconds after lift off. </p>
<p>It will have to be ready to go by 2026. But, before then, SpaceX will have to demonstrate that it can refuel in orbit and then land Starship on the Moon without crew. </p>
<p>At the same time, however, Blue Origin is also working on a lander, called Blue Moon. Blue Moon is due to be used as the Moon landing craft for the <a href="https://www.nasa.gov/news-release/nasa-shares-progress-toward-early-artemis-moon-missions-with-crew/">Artemis 5 and 6 missions in 2029 and 2030</a>. </p>
<p>Time will tell which lander can actually be ready for use first. But competition is always a good stimulator, and it could accelerate achievements. </p>
<p>Commercial companies supporting Nasa in the Artemis program will have to put a lot of attention into what to do and when. The lives of crew members are at stake here, so missions have to proceed in a safe and sustainable manner.</p>
<p>As with Apollo, Nasa is also trying to use the program to inspire the next generation of scientists, engineers and mathematicians. Baby boomers like myself are very proud to be “Apollo kids” who were inspired to study scientific subjects by those momentous achievements – particularly the first steps on another world, viewed through black and white TVs in July 1969.</p>
<h2>International competition</h2>
<p>China is also preparing itself, together with several other countries including Russia, to develop a lunar base for humans, called the International Lunar Research Station (ILRS). Beijing and its partners will include also private sectors players and governmental and non-governmental organisations, with an organisational scheme which is a first. </p>
<p>The Chinese program’s <a href="https://www.reuters.com/technology/space/china-offers-collaborate-lunar-mission-deadlines-loom-2023-10-03/">first human missions to the lunar surface are expected by 2030</a>. Among the sites where they want to land is the Moon’s south pole. Nasa also wants to land here, but few of Beijing’s choices are in overlap with the locations selected for Artemis. </p>
<p>The south pole is a target for both the US and China because countries want to extract the water ice that’s hidden in craters there. This water could be used for life support at lunar bases and to make rocket fuel, helping bring down the cost of space exploration. </p>
<p>Space programs are never on time, and postponements are normal. Space agencies are
more cautious nowadays, even more than before, because few tragedies we experienced in the past are obliging them to think very carefully before launching humans in space. </p>
<p>Safety of the crew is mandatory, and it must be always the first priority. So, if this is the reason why we have to wait a bit more before few human beings, after decades, will walk again on the Moon, I’m happy to wait for it. </p>
<p>Going to space has never been easy, as demonstrated by several uncrewed missions to the Moon over the last 12 months – both governmental and commercial – which didn’t make it. But perhaps it’s better we fail now while we are preparing for the new phase of humanity’s history. </p>
<p>The Moon will soon experience human beings on its surface again, working and living on a regular basis. But when humans go back there, this time it will be to stay.</p><img src="https://counter.theconversation.com/content/221996/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simonetta Di Pippo does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The US might be facing international competition to be first to return to the Moon.Simonetta Di Pippo, Director of the Space Economy Evolution Lab, Bocconi UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2206642024-01-22T01:03:09Z2024-01-22T01:03:09ZYou can pay to have your ashes buried on the moon. Just because you can doesn’t mean you should<p>When NASA attempted to return to the Moon for the first time in 50 years on <a href="https://blogs.nasa.gov/artemis/tag/commercial-lunar-payload-services/">January 8</a>, more was at risk than just US$108 million worth of development and equipment.</p>
<p>The agency earned the ire of the Native American Navajo people, who made a bid to stop the launch because of an unusual inclusion in the payload. </p>
<p>The Peregrine lander (which completed its controlled re-entry into the atmosphere <a href="https://www.nasa.gov/news-release/nasa-science-astrobotic-peregrine-mission-one-concludes/">late last week</a>) was carrying <a href="https://edition.cnn.com/2024/01/05/world/peregrine-moon-mission-navajo-nation-objection-human-remains-scn/index.html">human ashes</a>, including those of famed science fiction author <a href="https://www.smh.com.au/world/north-america/remains-of-sci-fi-legends-to-burn-in-earth-s-atmosphere-20240119-p5eyic.html">Arthur C. Clarke</a>. A commercial partnership also allowed paying customers to send their mementos to the Moon.</p>
<p>As space exploration becomes increasingly privatised and commercial, you can now send your favourite stuff to the Moon. But what does that mean, both ethically and legally?</p>
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Read more:
<a href="https://theconversation.com/privatised-moon-landings-the-two-us-missions-set-to-open-a-new-era-of-commercial-lunar-exploration-219546">Privatised Moon landings: the two US missions set to open a new era of commercial lunar exploration</a>
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<h2>The Moon open for business</h2>
<p>US company Astrobotic owns the Peregrine, which is the size of a small car. It ran into fatal <a href="https://www.npr.org/2024/01/14/1224723508/peregrine-moon-lander-heads-back-toward-earth-and-should-burn-up-in-the-atmosphe">fuel issues</a> shortly after being launched on Vulcan Centaur rocket from Cape Canaveral.</p>
<p>On board are “vanity canisters”. The idea arose <a href="https://group.dhl.com/content/dam/deutschepostdhl/en/media-relations/press-releases/2024/pr-dhl-moonbox-20240108.pdf">in a partnership</a> between the firm and global freight company DHL.</p>
<p>Under the deal, anyone can send two and a half centimetre by five centimetre package to the lunar surface for less than US$500. Apart from size, there were a few other limitations on what each package could contain.</p>
<p>Astrobotic, founded in 2007 and based in Pittsburgh, Pennsylvania, is one of several US companies providing commercial lunar payload services to NASA to deliver science and technology to the Moon. Peregrine was also carrying <a href="https://www.astrobotic.com/lunar-delivery/manifest/">scientific instruments</a> from six countries and many science teams.</p>
<p>Perhaps surprisingly, sending ashes into space is not new aboard suborbital and Earth orbital flights. </p>
<p>Two American companies make a business of the service starting at just a few thousand dollars – <a href="https://www.celestis.com/">Celestis</a> and <a href="https://elysiumspace.com/">Elysium Space</a>. The practice is embraced by many, including astronauts who have been in space. </p>
<p>A Moon burial (yes, you can buy one) costs more – around US$13,000.</p>
<p>Commercial payloads launched from US soil require <a href="https://www.faa.gov/space/licenses/payload_reviews">approval</a>, but that approval process only covers safety, national security, and foreign policy.</p>
<p>Peregrine, if it had made it, would have marked the first commercial lunar burial. It’s uncharted territory as other worlds become within reach, although it is not the first time it has come up. </p>
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Read more:
<a href="https://theconversation.com/earth-isnt-the-only-planet-with-seasons-but-they-can-look-wildly-different-on-other-worlds-216874">Earth isn't the only planet with seasons, but they can look wildly different on other worlds</a>
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<p>NASA pledged to consult in the future after an outcry from the Navajo when, 20 years ago, it carried some of Eugene Shoemaker’s ashes to the Moon aboard the Lunar Prospector probe. Like many other indigenous cultures, the Navajo Nation considers the Moon sacred and <a href="https://www.facebook.com/PresidentNygren/posts/892377286222557?ref=embed_post">opposes</a> using it as a memorial site. </p>
<p>However, NASA said in a press briefing it <a href="https://www.opb.org/article/2024/01/08/navajo-human-remains-moon/">had no control</a> over what was on Peregrine, highlighting the gaps between commercial enterprise and international space law. </p>
<h2>A legal minefield</h2>
<p>Another question concerns the rules in individual nations on where and how human ashes can be located, handled, and transported and how those could extend to space. For example, in Germany, ashes <a href="https://canada.diplo.de/ca-en/consular-services/08-OtherConsularServices/death/1101248">must be buried</a> in a cemetery.</p>
<p>With space privatisation accelerating, the ethical and legal maze deepens. </p>
<p>The Outer Space Treaty (OST) <a href="https://www.unoosa.org/pdf/gares/ARES_21_2222E.pdf">declares space</a> the “province of all mankind” while banning national appropriation. </p>
<p>It fails, however, to address what private companies and individuals can do. </p>
<p>The recent <a href="https://www.nasa.gov/artemis-accords/">Artemis Accords</a>, signed by 32 nations, expand protection to lunar sites of historical significance. But these protections only apply to governments, not commercial missions. </p>
<p>And no one owns the Moon to grant burial rights, or any other world or celestial body. </p>
<p>The treaty requires states to authorise and supervise activities in space. It requires “due regard” for the interests of other states. </p>
<p>Many countries have space law that includes grounds for refusing payload items not in their national interest, for example <a href="https://www.peraturan.go.id/files2/uu-no-21-tahun-2013_terjemah.pdf">Indonesia</a> and <a href="https://www.mbie.govt.nz/science-and-technology/space/our-regulatory-regime/#:%7E:text=The%20Act%20regulates%20%E2%80%94%20through%20licences,Innovation%20and%20Employment%20(MBIE)">New Zealand</a>. </p>
<p>Nations apparently without such consideration, including Australia and the US, may need to consider expanding this template with the emergence of the commercial world in a traditionally governmental arena.</p>
<h2>Where to draw a line?</h2>
<p>Earth’s orbit is already clogged with defunct satellites and, further out, items like <a href="https://www.cnet.com/science/space/heres-where-elon-musks-tesla-roadster-is-after-five-years-in-space/">Elon Musk’s Tesla</a>. </p>
<p><iframe id="iDyuh" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/iDyuh/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>We have already spread space probes across other worlds, including the Moon, Mars, Titan, and Venus, but much may be <a href="https://www.planetary.org/articles/space-trash">treasure rather than junk</a>, according to space archaeologist Alice Gorman. </p>
<p>For example, the Apollo astronauts left official mementos, such as a plaque marking the first human footsteps on the lunar surface. Some have left personal ones, too, like Apollo 16’s Charles Duke, who left a <a href="https://www.rmg.co.uk/stories/topics/strange-things-humans-have-left-on-moon">framed family photo</a>.</p>
<p>However, sending a clipping of your hair or the ashes of your pet dog to the Moon may not qualify as culturally and historically important. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-the-moons-south-pole-to-an-ice-covered-ocean-world-several-exciting-space-missions-are-slated-for-launch-in-2024-218000">From the Moon's south pole to an ice-covered ocean world, several exciting space missions are slated for launch in 2024</a>
</strong>
</em>
</p>
<hr>
<p>The problem, therefore, is where we want to place a line in the sand as we step out into the cosmos onto the shorelines of other worlds. </p>
<p>We cannot turn back the clock on private space enterprise, nor should we. </p>
<p>But this failed mission with ashes and vanity payloads exemplifies the unexplored questions in the legal and ethical infrastructure to support commercial activities. </p>
<p>It is worth pausing for thought on future commercialisation such as mining asteroids and the eventual colonisation of space.</p><img src="https://counter.theconversation.com/content/220664/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Carol Oliver does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Sending human ashes and personal mementoes to the Moon is now possible, but it opens up a maze of legal and ethical conundrums.Carol Oliver, Professor in Science Communication and Astrobiology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2215702024-01-21T14:03:29Z2024-01-21T14:03:29ZJapan is now the 5th country to land on the Moon – the technology used will lend itself to future lunar missions<figure><img src="https://images.theconversation.com/files/570427/original/file-20240119-27-p6esw0.jpg?ixlib=rb-1.1.0&rect=249%2C0%2C4597%2C3248&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Data from the SLIM mission projected at JAXA's Sagamihara Campus during the craft's landing. </span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/JapanMoonLanding/03b3de9eaaba4dda9bfbe0236b3b28db/photo?Query=slim&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=3883&currentItemNo=1">AP Photo/Eugene Hoshiko</a></span></figcaption></figure><p>Japan landed its <a href="https://global.jaxa.jp/projects/sas/slim/">Smart Lander for Investigating the Moon</a>, or SLIM, craft on the surface of the Moon on Jan. 20, 2024. Despite a power issue with the lander, the event holds both political and technical importance. It’s Japan’s first lunar landing – making it only the fifth country in the world to successfully land on the Moon. This is a significant achievement and solidifies Japan’s position as a leader in space technology. </p>
<p>While the craft <a href="https://www.youtube.com/watch?v=nvXLt3ET9mE">landed successfully on the lunar surface</a> and deployed its rovers, SLIM’s solar cells were not functioning properly – meaning that the craft could likely <a href="https://www.nytimes.com/2024/01/12/science/japan-slim-moon-landing.html">only operate for a few hours</a>. </p>
<p>I’m a <a href="https://scholar.google.com/citations?user=aESo-coAAAAJ&hl=en">scholar of international affairs</a> who studies space. Like NASA and other space agencies, the <a href="https://global.jaxa.jp/">Japan Aerospace Exploration Agency, or JAXA</a>, wants to advance research and technology by demonstrating new techniques and collecting scientific data. The landing is also a part of something bigger – a <a href="https://theconversation.com/returning-to-the-moon-can-benefit-commercial-military-and-political-sectors-a-space-policy-expert-explains-209300">growing global interest in lunar activity</a>. </p>
<h2>Precision technology</h2>
<p>Japan’s achievement isn’t only symbolic – Japan is demonstrating a number of new technologies with the lander. The name, Smart Lander for Investigating the Moon, refers to the spacecraft’s <a href="https://global.jaxa.jp/countdown/slim/SLIM-mediakit-EN_2310.pdf">new precision-landing technology</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/UEZO4jj7v0I?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">SLIM’s landing technology allowed it to detect and avoid potential obstacles.</span></figcaption>
</figure>
<p>This technology could assist future landings by allowing spacecraft to land in relatively small areas amid rocky or uneven terrain, rather than having to find large clearings. This ability will be particularly important in the future as countries focus on very specific <a href="https://theconversation.com/scientists-suspect-theres-ice-hiding-on-the-moon-and-a-host-of-missions-from-the-us-and-beyond-are-searching-for-it-216060">areas of interest</a> at <a href="https://theconversation.com/chandrayaan-3s-measurements-of-sulfur-open-the-doors-for-lunar-science-and-exploration-212950">the lunar south pole</a>. </p>
<p>The lander also carried two small rovers, each of which will demonstrate a new technology for moving on the Moon. </p>
<p><a href="https://www.planetary.org/space-missions/slim-japans-precision-lunar-lander">Lunar Excursion Vehicle 1</a> includes a camera, as well as scientific equipment, and uses a hopping mechanism to maneuver on the Moon. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Artist's illustration of Japan's SLIM lander, which looks like a metal box with cones and lights on one end, attempting its lunar touchdown" src="https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570455/original/file-20240120-25-vl1x3l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An illustration of the SLIM lander touching down.</span>
<span class="attribution"><span class="source">JAXA/ISAS</span></span>
</figcaption>
</figure>
<p><a href="https://global.jaxa.jp/activity/pr/jaxas/no088/03.html">Lunar Excursion Vehicle 2</a>, developed in a partnership among government, industry, and academia, is a sphere small enough to fit in the palm of your hand. Once on the surface, its two halves separate slightly, allowing it to roll around.</p>
<p>SLIM is designed to land <a href="https://global.jaxa.jp/countdown/slim/SLIM-mediakit-EN_2310.pdf">within a 328-foot (100-meter) zone</a>, far smaller than previous lunar landers which have had landing zones spanning multiple kilometers. </p>
<p>SLIM used a <a href="https://global.jaxa.jp/countdown/slim/SLIM-mediakit-EN_2310.pdf">vision-based navigation system</a> that took images of the lunar surface. Its system rapidly compared these images to crater patterns on lunar maps that JAXA developed with data from previous missions. </p>
<p>As countries identify areas that are most likely to hold useful resources, such as <a href="https://theconversation.com/scientists-suspect-theres-ice-hiding-on-the-moon-and-a-host-of-missions-from-the-us-and-beyond-are-searching-for-it-216060">water in the form of ice</a>, precision landing technology will allow agencies to avoid nearby hazards and reach these areas without incident.</p>
<h2>International relations back on Earth</h2>
<p>There is a geopolitical element to these activities. China, India and Japan – the three nations that have successfully landed on the Moon since 2000 – engage in regional competition across a number of areas, including space. In addition to regional considerations, these accomplishments help to establish nations as leaders on a global scale – capable of something that few nations have ever done. </p>
<p>Japan’s launch comes only six months after <a href="https://theconversation.com/indias-chandrayaan-3-landed-on-the-south-pole-of-the-moon-a-space-policy-expert-explains-what-this-means-for-india-and-the-global-race-to-the-moon-212171">India’s Moon landing</a> and just weeks after <a href="https://www.nytimes.com/2024/01/18/science/moon-lander-peregrine-nasa.html">a failed attempt</a> by a U.S. company, Astrobotic. </p>
<p><a href="https://www.reuters.com/business/aerospace-defense/russias-moon-mission-falters-after-problem-entering-pre-landing-orbit-2023-08-20/">Both Russia</a> and <a href="https://ispace-inc.com/news-en/?p=4655">the private company iSpace</a> made unsuccessful landing attempts in 2023. Japan’s success in landing on the Moon – even with solar panel issues shortening the timeline for the mission – demonstrates that JAXA is a major player in this global endeavor. </p>
<p>Despite recent setbacks, such as <a href="https://www.nasa.gov/news-release/nasa-shares-progress-toward-early-artemis-moon-missions-with-crew/">NASA announcing delays</a> to its next Artemis mission, the U.S. is still a clear leader in space and lunar exploration. NASA has <a href="https://www.nasa.gov/general/does-anything-orbit-the-moon-we-asked-a-nasa-technologist/">multiple spacecraft orbiting the Moon</a> right now, and it’s already successfully launched the <a href="https://www.nasa.gov/humans-in-space/space-launch-system/">SLS rocket</a>, which is capable of taking humans back to the Moon. </p>
<p>NASA is developing very large and complex systems internally – like the <a href="https://www.nasa.gov/mission/gateway/">Gateway space station</a>, planned to orbit near the Moon, and the infrastructure for the <a href="https://theconversation.com/meet-the-next-four-people-headed-to-the-moon-how-the-diverse-crew-of-artemis-ii-shows-nasas-plan-for-the-future-of-space-exploration-203214">Artemis human Moon missions</a>. It’s not uncommon for these large and complex efforts to experience some delays. </p>
<p>NASA has also turned many smaller-scale efforts over to commercial entities lately – like in the <a href="https://www.nasa.gov/commercial-lunar-payload-services/">Commercial Lunar Payload Services program</a> that supported Astrobotic’s attempt. This is a new approach that involves some risk, but provides the opportunity for commercial innovation and growth of the <a href="https://www.nasa.gov/humans-in-space/growing-the-lunar-economy/">lunar economy</a> while giving NASA the ability to focus on big, complex aspects of the mission.</p>
<p>With regard to the Moon, JAXA has partnered with the U.S. and taken on a very important component of the Artemis missions – the development of a <a href="https://www.toyota-europe.com/news/2023/lunar-cruiser">pressurized lunar rover</a>. This is a new and complex technology that will be critical to human missions on the Moon in coming years.</p><img src="https://counter.theconversation.com/content/221570/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mariel Borowitz receives funding from the U.S. National Aeronautics and Space Administration and the U.S. Department of Defense. </span></em></p>Japan is one of several countries that weren’t part of the space race of the 1950s and 1960s looking toward the Moon. They’ve now become the 5th country to have landed on its surface.Mariel Borowitz, Associate Professor of International Affairs, Georgia Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2212232024-01-19T01:58:47Z2024-01-19T01:58:47ZJapan is about to land its first lunar probe. As more nations race to the Moon, how will we keep the peace?<figure><img src="https://images.theconversation.com/files/570001/original/file-20240118-23-zlvufg.jpg?ixlib=rb-1.1.0&rect=287%2C109%2C1342%2C968&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Illustration of the Japanese moon
lander separating in orbit.</span> <span class="attribution"><a class="source" href="https://jda.jaxa.jp/result.php?lang=e&id=99a1760a907a60514deaad8181c9a853">JAXA</a></span></figcaption></figure><p>Early on Saturday, January 20 2024, Japan hopes to become the fifth country to successfully <a href="https://global.jaxa.jp/press/2024/01/20240115-1_e.html">land a probe</a> on the Moon. To date, the United States, the Soviet Union, China and India have preceded the East Asian nation.</p>
<p>Launched in September 2023 by the Japanese Aerospace Exploration Agency (<a href="https://global.jaxa.jp/">JAXA</a>), the Japanese Smart Lander for Investigating Moon (SLIM) is set to touch down around 02:20am AEDT. Trialling a novel landing technique with pinpoint accuracy, it is poised to settle on a gently sloped crater rim – a first in lunar exploration. </p>
<p>JAXA celebrates the mission as a technology demonstrator. The agency’s main aim is to practice near-real-time visual precision landing. The newly developed landing technology would allow them to touch down anywhere they want, rather than only where the terrain is favourable. </p>
<p>Plans for a follow-up expedition, the Lunar Polar Exploration probe (<a href="https://global.jaxa.jp/activity/pr/jaxas/no092/02.html">LUPEX</a>), are well advanced. That mission <a href="https://economictimes.indiatimes.com/news/science/isro-working-on-ambitious-lunar-missions-lupex-chandrayaan-4-official/articleshow/105292411.cms">will be developed jointly</a> with the Indian Space Research Organisation (ISRO).</p>
<h2>The Moon is a busy target</h2>
<p>In recent years, the Moon has become a key target for exploration missions. For instance, just last year we witnessed Russia’s <a href="https://theconversation.com/russia-has-declared-a-new-space-race-hoping-to-join-forces-with-china-heres-why-thats-unlikely-211993">attempted landing</a> of its Luna 25 probe and the first successful ISRO Moon shot, <a href="https://www.isro.gov.in/Chandrayaan3_Details.html">Chandrayaan-3</a>. </p>
<p>Meanwhile, the US aims to return humans to the Moon through their <a href="https://www.nasa.gov/specials/artemis/">Artemis</a> programme while also supporting <a href="https://phys.org/news/2024-01-lunar-lander-years-rockets-moon.html">commercial companies</a> in their quest to reestablish a viable presence there.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/scientists-and-space-agencies-are-shooting-for-the-moon-5-essential-reads-on-modern-lunar-missions-216808">Scientists and space agencies are shooting for the Moon -- 5 essential reads on modern lunar missions</a>
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<p>NASA and its international partners aim to eventually place a crewed space station in lunar orbit, the <a href="https://www.nasa.gov/reference/nasas-gateway-program/">Gateway Lunar Space Station</a>. </p>
<p>Simultaneously, China continues its successful, carefully planned <a href="https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program">Chang'e project</a>. The Asian powerhouse is working towards establishing its own <a href="https://en.wikipedia.org/wiki/International_Lunar_Research_Station">International Lunar Research Station</a>. That Chinese–Russian project is <a href="https://spacenews.com/china-russia-enter-mou-on-international-lunar-research-station/">promoted</a> as “open to all interested countries and international partners”.</p>
<h2>‘Peaceful intentions’</h2>
<p>To date, the leading spacefaring nations have gone to great lengths to publicly assure us that their intentions in space are peaceful. Yet, last year Yury Borisov of Russia’s space agency Roscosmos <a href="https://www.abc.net.au/news/2023-08-22/russia-declares-the-race-has-begun-for-moons-resources/102757808">bluntly stated</a>: </p>
<blockquote>
<p>This is not just about the prestige of the country and the achievement of some geopolitical goals. This is about ensuring defensive capabilities and achieving technological sovereignty.</p>
</blockquote>
<p>Borisov’s comments should not be read in isolation, however. US officials have made similar assertions. In July last year, the US assistant secretary of defense for space policy, John F. Plumb, was <a href="https://www.defense.gov/News/News-Stories/Article/Article/3465982/space-integral-to-the-dod-way-of-war-policy-chief-says/">equally blunt</a>:</p>
<blockquote>
<p>Space is in our DNA for the military. It’s absolutely essential to our way of war.</p>
</blockquote>
<p>Such official commentary is clearly anathema to the purported peaceful intentions expressed by officials elsewhere in their respective national hierarchies. Similarly, to safeguard its national interests and <a href="https://www.reuters.com/article/idUSBREA3E03H/">encouraged</a> by President Xi Jinping himself, China has been <a href="https://www.airuniversity.af.edu/Portals/10/SSQ/documents/Volume-06_Issue-1/Cheng.pdf">fine-tuning</a> its own military space strategy. </p>
<p>The Moon is a large target, which to date is only accessible to a small number of actors. Yet, ever since <a href="https://moon.nasa.gov/inside-and-out/composition/water-and-ices/">evidence of water was found</a> near the Moon’s south pole, much effort has focused on finding ways to land safely in the Moon’s southern hemisphere.</p>
<p>With commercial actors and national interests thrown into the mix, we ought to consider the geopolitical implications of this new space race.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Foreground of a grey surface with a half lit Earth in the distance hanging in a black sky" src="https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570002/original/file-20240118-15-r3cidd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An earthrise seen from the surface of the Moon in July 1969 during the Apollo 11 mission.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/image-detail/amf-as11-44-6550/">NASA</a></span>
</figcaption>
</figure>
<h2>Who keeps the peace in space?</h2>
<p>The 1967 <a href="https://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html">Outer Space Treaty</a> remains the defining legal document governing strategic conduct in space.
To date, its has been ratified by 114 countries and 22 other signatories, including all major spacefaring nations.</p>
<p>However, new technological developments and the increasing presence of private space companies have prompted some to suggest that the <a href="https://ace-usa.org/blog/foreign-policy-region/space-oceans-and-polar-regions/failures-and-successes-of-the-outer-space-treaty/">treaty has become outdated</a>.</p>
<p>Therefore, the US has independently developed a new international agreement, which it says is focused on common principles, guidelines and best practices applicable to the safe exploration of the Moon and beyond: the <a href="https://www.nasa.gov/artemis-accords/">Artemis Accords</a>.</p>
<p>Thus far, 33 countries have signed the agreement, but neither Russia nor China have acceded. Given the prevailing political differences, there is currently no clear way forward to bring all parties to the same table.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/outer-space-rwanda-and-nigeria-sign-an-accord-for-more-responsible-exploration-why-this-matters-203202">Outer space: Rwanda and Nigeria sign an accord for more responsible exploration – why this matters</a>
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<p>Although the Moon remains uncrowded, sustained exploration, human occupation and commercial exploitation will increase the likelihood of encounters on the lunar surface (or in orbit) between competing parties, or even between nations engaged in major conflict on Earth.</p>
<p>While the Outer Space Treaty envisions peaceful use of the space environment, the proliferation of military hardware in low Earth orbit implies that any such adverse encounter might result in <a href="https://www.aph.gov.au/About_Parliament/Parliamentary_departments/Parliamentary_Library/pubs/BriefingBook47p/OngoingMilitarisationSpace">devastating consequences</a>. </p>
<p>At present, there are few safeguards to prevent wholesale conflict escalating beyond our home planet. Diplomatic efforts have been largely <a href="https://www.scientificamerican.com/article/how-do-we-prevent-war-in-space/">lacklustre</a>. </p>
<p>Despite <a href="https://www.ucsusa.org/about/news/space-force-would-trigger-arms-race">urgent recommendations</a> from across the political spectrum to practice caution and avoid escalation, the world continues on a path towards an increasingly volatile space environment. </p>
<p>Fortunately, in this highly complex environment cool heads have thus far prevailed in resolving potential conflicts in space. As a case in point, we should probably be encouraged by the sustained multilateral collaboration on the <a href="https://www.nature.com/articles/d41586-023-01558-0">International Space Station</a>, despite the parties’ radically opposite stances on Earth.</p>
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<p><em>The author gratefully acknowledges constructive criticism on an earlier draft of this article by Dr. Fabio Favata.</em></p><img src="https://counter.theconversation.com/content/221223/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard de Grijs does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Japan’s space agency is landing its first lunar probe this week. This makes the Moon an increasingly busy target for spacefaring nations – with conflicting political stances among them.Richard de Grijs, Professor of Astrophysics, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.