tag:theconversation.com,2011:/au/topics/solar-flare-2511/articlesSolar flare – The Conversation2023-10-02T12:29:02Ztag:theconversation.com,2011:article/2058092023-10-02T12:29:02Z2023-10-02T12:29:02ZHow do astronomers know the age of the planets and stars?<figure><img src="https://images.theconversation.com/files/529821/original/file-20230602-6875-7ttf8v.jpg?ixlib=rb-1.1.0&rect=1%2C16%2C1005%2C671&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Astronomers can estimate ages for stars outside the Solar System, but not planets.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-constellation-sagittarius-taken-from-the-u-s-naval-news-photo/615295876?adppopup=true">Corbis Historical 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">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<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><strong>How do we know the age of the planets and stars? – Swara D., age 13, Thane, India</strong></p>
</blockquote>
<hr>
<p>Measuring the ages of planets and stars helps scientists understand when they formed and how they change – and, in the case of planets, if <a href="https://theconversation.com/ancestor-of-all-life-on-earth-evolved-earlier-than-we-thought-according-to-our-new-timescale-101752">life has had time to have evolved on them</a>.</p>
<p>Unfortunately, age is hard to measure for objects in space.</p>
<p>Stars like the Sun maintain the same <a href="https://en.wikipedia.org/wiki/Stellar_evolution">brightness, temperature and size for billions of years</a>. Planet properties <a href="https://en.wikipedia.org/wiki/Planetary_equilibrium_temperature">like temperature</a> are often set by the star they orbit rather than their own age and evolution.</p>
<p>Determining the age of a star or planet can be as hard as guessing the age of a person who looks exactly the same from childhood to retirement. </p>
<h2>Sussing out a star’s age</h2>
<p>Fortunately, <a href="http://astronomy.nmsu.edu/jasonj/565/docs/11_07.pdf">stars change subtly</a> in brightness and color over time. With very accurate measurements, astronomers can compare these measurements of a star to <a href="https://doi.org/10.3847/0067-0049/222/1/8">mathematical models</a> that predict what happens to stars as they get older and estimate an age from there. </p>
<p>Stars don’t just glow, they also spin. Over time, <a href="https://doi.org/10.1086/151310">their spinning slows down</a>, similar to how a spinning wheel slows down when it encounters friction. By comparing the spin speeds of stars of different ages, astronomers have been able to <a href="https://doi.org/10.1086/367639">create mathematical relationships for the ages of stars</a>, a method known as <a href="https://en.wikipedia.org/wiki/Gyrochronology">gyrochronology</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close up image of the Sun in outer space" src="https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=567&fit=crop&dpr=1 600w, https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=567&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=567&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=713&fit=crop&dpr=1 754w, https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=713&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/530378/original/file-20230606-25-mkkjms.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=713&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Researchers estimate the Sun is 4.58 billion years old.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-this-handout-photo-provided-by-nasa-a-solar-and-news-photo/2740385?adppopup=true">NASA via GettyImages</a></span>
</figcaption>
</figure>
<p>A star’s spin also generates a strong magnetic field and produces magnetic activity, such as <a href="https://en.wikipedia.org/wiki/Solar_flare">stellar flares</a> – powerful bursts of energy and light that occur on stars’ surfaces. A steady decline in magnetic activity from a star can also help estimate its age.</p>
<p>A more advanced method for determining the ages of stars is called <a href="https://en.wikipedia.org/wiki/Asteroseismology">asteroseismology</a>, or star shaking. Astronomers study vibrations on the surfaces of stars caused by waves that travel through their interiors. Young stars have different vibrational patterns than old stars. By using this method, <a href="https://doi.org/10.1051/0004-6361/201526419">astronomers have estimated</a> the Sun to be 4.58 billion years old.</p>
<h2>Piecing together a planet’s age</h2>
<p>In the solar system, <a href="https://en.wikipedia.org/wiki/Radionuclide">radionuclides</a> are the key to dating planets. These are special atoms that slowly release energy over a long period of time. As natural clocks, radionuclides help scientists determine the ages of all kinds of things, from <a href="https://www.nps.gov/subjects/geology/radiometric-age-dating.htm">rocks</a> to <a href="https://theconversation.com/radiocarbon-dating-only-works-half-the-time-we-may-have-found-the-solution-189493">bones</a> and <a href="https://physicsworld.com/a/archaeological-dating-by-re-firing-ancient-pots/">pottery</a>.</p>
<p>Using this method, scientists have determined that the oldest known meteorite is <a href="https://doi.org/10.1073/pnas.2026129118">4.57 billion years old</a>, almost identical to the Sun’s asteroseismology measurement of 4.58 billion years. The oldest known rocks on Earth have slightly younger ages of <a href="https://doi.org/10.1038/35051550">4.40 billion years</a>.
Similarly, soil brought back from the Moon during the Apollo missions had <a href="https://doi.org/10.1016/0012-821X(70)90093-2">radionuclide ages of up to 4.6 billion years</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close up image of craters on the surface of the moon." src="https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/535816/original/file-20230705-7861-tqlx1p.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">Craters on the moon’s surface.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/mondoberfl%C3%A4che-royalty-free-image/1174421451?phrase=crater+moon&adppopup=true">Tomekbudujedomek/Moment via Getty Images</a></span>
</figcaption>
</figure>
<p>Although studying radionuclides is a powerful method for measuring the ages of planets, it usually requires having a rock in hand. Typically, astronomers only have a picture of a planet to go by. Astronomers often determine the ages of rocky space objects like Mars or the Moon by <a href="https://en.wikipedia.org/wiki/Crater_counting#:%7E:text=Crater%20counting%20is%20a%20method,rate%20that%20is%20assumed%20known.">counting their craters</a>. Older surfaces have more craters than younger surfaces. However, erosion from water, wind, <a href="https://phys.org/news/2021-09-cosmic-rays-erode-largest-interstellar.html">cosmic rays</a> and lava flow from volcanoes can wipe away evidence of earlier impacts.</p>
<p>Aging techniques don’t work for giant planets like Jupiter that have deeply buried surfaces. However, astronomers can estimate their ages by <a href="https://doi.org/10.1016/j.icarus.2020.114184">counting craters on their moons</a> or studying the <a href="https://doi.org/10.1073/pnas.1704461114">distribution of certain classes of meteorites</a> scattered by them, which are consistent with radionuclide and cratering methods for rocky planets.</p>
<p>We cannot yet directly measure the ages of planets outside our solar system with current technology.</p>
<h2>How accurate are these estimates?</h2>
<p>Our own solar system provides the best check for accuracy, since astronomers can compare the radionuclide ages of rocks on the Earth, Moon, or asteroids to the asteroseismology age of the Sun, and these match very well. </p>
<p>Stars in clusters like the <a href="https://en.wikipedia.org/wiki/Pleiades">Pleiades</a> or <a href="https://en.wikipedia.org/wiki/Omega_Centauri">Omega Centauri</a> are believed to have all formed at roughly the same time, so age estimates for individual stars in these clusters should be the same. In some stars, <a href="https://ui.adsabs.harvard.edu/abs/2023ApJ...948..122S/abstract">astronomers can detect</a> radionuclides like uranium – a heavy metal found in rocks and soil – in their atmospheres, which have been used to check the ages from other methods. </p>
<p>Astronomers believe planets are roughly the same age as their host stars, so improving methods to determine a star’s age helps determine a planet’s age as well. By studying subtle clues, it’s possible to make an educated guess of the age of an otherwise steadfast star.</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/205809/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Burgasser receives funding from NASA and the National Science Foundation.</span></em></p>Measuring the ages of planets and stars is tricky. An observational astrophysicist describes the subtle clues that provide good estimates for how old different space objects are.Adam Burgasser, Professor of Astronomy & Astrophysics, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1930802022-10-25T23:04:46Z2022-10-25T23:04:46ZRadioactive traces in tree rings reveal Earth’s history of unexplained ‘radiation storms’<figure><img src="https://images.theconversation.com/files/491154/original/file-20221023-40716-6xlwd2.jpg?ixlib=rb-1.1.0&rect=52%2C37%2C4940%2C3952&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">University of Queensland</span></span></figcaption></figure><p>In searching for planets and studying their stars, I’ve had the privilege to use some of the world’s great telescopes. However, our team has recently turned to an even larger system to study the cosmos: Earth’s forests. </p>
<p>We analysed radioactive signatures left in tree rings around the world to study mysterious “radiation storms” that have swept over Earth half a dozen times in the past 10,000 years or so.</p>
<p>Our results, published today in <a href="https://doi.org/10.1098/rspa.2022.0497">Proceedings of the Royal Society A</a>, rule out “solar superflares” as the culprit – but the true cause remains unknown.</p>
<h2>A history written in tree rings</h2>
<p>When high-energy radiation strikes the upper atmosphere it turns nitrogen atoms into radioactive carbon-14, or radiocarbon. The radiocarbon then filters through the air and the oceans, into sediments and bogs, into you and me, into animals and plants - including hardwoods with their yearly tree rings. </p>
<p>To archaeologists, radiocarbon is a godsend. After it is created, carbon-14 slowly and steadily decays back into nitrogen – which means it can be used as a clock to measure the age of organic samples, in what is called <a href="https://www.nature.com/articles/s43586-021-00058-7">radiocarbon dating</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-what-is-radiocarbon-dating-and-how-does-it-work-9690">Explainer: what is radiocarbon dating and how does it work?</a>
</strong>
</em>
</p>
<hr>
<p>To astronomers, this is equally valuable. Tree rings give a year-by-year record of high-energy particles called “cosmic rays” <a href="https://www.nature.com/articles/s41561-020-00674-0">going back millennia</a>. </p>
<p>The magnetic fields of Earth and the Sun shield us from cosmic rays shooting through the Galaxy. More cosmic rays reach Earth when these magnetic fields are weaker, and fewer when the fields are stronger.</p>
<p>This means the rise and fall of carbon-14 levels in tree rings encodes a history of <a href="https://sci-hub.se/10.1126/science.207.4426.11">the 11-year cycle of the solar dynamo</a> (which creates the Sun’s magnetic field) and the reversals of <a href="https://www.science.org/doi/full/10.1126/science.abb8677">Earth’s magnetic field</a>. </p>
<h2>Miyake events</h2>
<p>But tree rings also record events we cannot presently explain. In 2012, Japanese physicist Fusa Miyake <a href="https://ui.adsabs.harvard.edu/abs/2012Natur.486..240M/abstract">discovered a spike</a> in the radiocarbon content of tree rings from 774 AD. It was so big that several ordinary years’ worth of cosmic rays must have arrived all at once. </p>
<p>As more teams have joined the search, tree ring evidence has been uncovered of further “Miyake events”: from <a href="https://ui.adsabs.harvard.edu/abs/2013NatCo...4.1748M/abstract">993 AD</a> and <a href="https://www.cambridge.org/core/journals/radiocarbon/article/relationship-between-solar-activity-and-14c-peaks-in-ad-775-ad-994-and-660-bc/EFBDD78DEFAAA02B1CB9C3A24933B912">663 BC</a>, and prehistoric events in <a href="https://www.nature.com/articles/s41467-022-28804-9">5259 BC</a>, <a href="https://ui.adsabs.harvard.edu/abs/2021GeoRL..4893419M/abstract">5410 BC</a>, and <a href="https://www.nature.com/articles/s41467-021-27891-4">7176 BC</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-large-solar-storm-could-knock-out-the-power-grid-and-the-internet-an-electrical-engineer-explains-how-177982">A large solar storm could knock out the power grid and the internet – an electrical engineer explains how</a>
</strong>
</em>
</p>
<hr>
<p>These have already led to a revolution in archaeology. Finding one of these short, sharp spikes in an ancient sample <a href="https://royalsocietypublishing.org/doi/10.1098/rspa.2016.0263">pins its date down to a single year</a>, instead of the decades or centuries of uncertainty from ordinary radiocarbon dating. </p>
<p>Among other things, our colleagues have used the 993 AD event <a href="https://www.nature.com/articles/s41586-021-03972-8">to reveal the exact year</a> of the first European settlement in the Americas, the Viking village at L'Anse aux Meadows in Newfoundland: 1021 AD. </p>
<h2>Could huge radiation pulses happen again?</h2>
<p>In physics and astronomy, these Miyake events remain a mystery. </p>
<p>How do you get such a huge pulse of radiation? A flurry of papers have blamed supernovae, <a href="https://ui.adsabs.harvard.edu/abs/2013MNRAS.430...32H">gamma-ray bursts</a>, <a href="https://ui.adsabs.harvard.edu/abs/2019ApJ...887..202W/abstract">explosions from magnetised neutron stars</a>, and even <a href="https://www.nature.com/articles/srep03728">comets</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photograph of solar flares emanating from the Sun." src="https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=491&fit=crop&dpr=1 600w, https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=491&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=491&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=617&fit=crop&dpr=1 754w, https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=617&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/491521/original/file-20221025-18-a2bs48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=617&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Could ‘solar superflares’ be responsible for radiocarbon spikes in tree rings?</span>
<span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/images/pia21958-major-solar-flare">NASA / GSFC / Solar Dynamics Observatory</a></span>
</figcaption>
</figure>
<p>However, the <a href="https://ui.adsabs.harvard.edu/abs/2013A%26A...552L...3U/abstract">most widely accepted explanation</a> is that Miyake events are “solar superflares”. These hypothetical eruptions from the Sun would be perhaps 50–100 times more energetic than the biggest recorded in the modern era, the <a href="https://en.wikipedia.org/wiki/Carrington_Event">Carrington Event</a> of 1859. </p>
<p>If an event like this occurred today, it would <a href="https://astronomy.com/news/2021/09/understanding-just-how-big-solar-flares-can-get">devastate power grids, telecommunications, and satellites</a>. If these occur randomly, around once every thousand years, that is a 1% chance per decade – a serious risk. </p>
<h2>Noisy data</h2>
<p>Our team at UQ set out to sift through all the available tree ring data and pull out the intensity, timing, and duration of Miyake events. </p>
<p>To do this we had to develop software to solve a <a href="https://johncarlosbaez.wordpress.com/2012/07/24/carbon-cycle-box-models/">system of equations</a> that model how radiocarbon filters through the entire <a href="https://en.wikipedia.org/wiki/Carbon_cycle">global carbon cycle</a>, to work out what fraction ends up in trees in what years, as opposed to the oceans, bogs, or you and me. </p>
<p>Working with archaeologists, we have just released the first reproducible, systematic study of <a href="https://github.com/qingyuanzhang3/radiocarbon_workflow/tree/main/data">all 98 trees of published data</a> on Miyake events. We have also released <a href="https://sharmallama.github.io/ticktack">open source modelling software</a> as a platform for future work.</p>
<h2>Storms of solar flares</h2>
<p>Our results confirm each event delivers between one and four ordinary years’ worth of radiation in one go. <a href="https://www.nature.com/articles/s41467-018-05883-1">Earlier research</a> suggested trees closer to Earth’s poles recorded a bigger spike – which is what we would expect if solar superflares are responsible – but our work, looking at a larger sample of trees, shows this is not the case.</p>
<p>We also found these events can arrive at any point in the Sun’s 11-year activity cycle. Solar flares, on the other hand, <a href="https://link.springer.com/article/10.1007/s11207-021-01831-3">tend to happen</a> around <a href="https://arxiv.org/abs/2207.12787v2">the peak of the cycle</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-is-the-sun-going-quiet-22155">Why is the sun going quiet?</a>
</strong>
</em>
</p>
<hr>
<p>Most puzzling, a couple of the spikes seem to take longer than can be explained by the slow creep of new radiocarbon through the carbon cycle. This suggests that either the events can sometimes take longer than a year, which is not expected for a giant solar flare, or the growing seasons of the trees are not as even as previously thought.</p>
<p>For my money, the Sun is still the most likely culprit for Miyake events. However, our results suggest we’re seeing something more like a storm of solar flares rather than one huge superflare. </p>
<p>To pin down what exactly happens in these events, we will need more data to give us a better picture of the events we already know about. To obtain this data, we will need more tree rings – and also other sources such as <a href="https://ui.adsabs.harvard.edu/abs/2015NatCo...6.8611M/abstract">ice cores from the Arctic and Antarctic</a>.</p>
<p>This is truly interdisciplinary science. Normally I think about beautifully clean, precise telescopes: it is much harder to understand the complex, interconnected Earth.</p><img src="https://counter.theconversation.com/content/193080/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benjamin Pope receives funding from the Australian Research Council and the Big Questions Institute. </span></em></p>Half a dozen times in the past 10,000 years, enigmatic ‘Miyake events’ have showered Earth with cosmic rays.Benjamin Pope, ARC DECRA Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1779822022-03-18T12:31:42Z2022-03-18T12:31:42ZA large solar storm could knock out the power grid and the internet – an electrical engineer explains how<figure><img src="https://images.theconversation.com/files/452927/original/file-20220317-22992-n1ppek.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1500%2C997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Typical amounts of solar particles hitting the earth's magnetosphere can be beautiful, but too much could be catastrophic.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Northern_Lights_-_Aurora_Borealis_Norway_Ringvass%C3%B8ya_Troms%C3%B8.jpg">Svein-Magne Tunli - tunliweb.no/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>On Sept. 1 and 2, 1859, telegraph systems around the world failed catastrophically. The operators of the telegraphs reported receiving electrical shocks, telegraph paper catching fire, and being able to operate equipment <a href="https://arstechnica.com/science/2012/05/1859s-great-auroral-stormthe-week-the-sun-touched-the-earth/">with batteries disconnected</a>. During the evenings, the aurora borealis, more commonly known as the northern lights, could be seen as far south as Colombia. Typically, these lights are only visible at higher latitudes, in northern Canada, Scandinavia and Siberia.</p>
<p>What the world experienced that day, now known as the <a href="https://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event">Carrington Event</a>, was a massive <a href="https://theconversation.com/solar-storms-can-destroy-satellites-with-ease-a-space-weather-expert-explains-the-science-177510">geomagnetic storm</a>. These storms occur when a large bubble of superheated gas called plasma is ejected from the surface of the sun and hits the Earth. This bubble is known as a coronal mass ejection. </p>
<p>The plasma of a coronal mass ejection consists of a cloud of protons and electrons, which are electrically charged particles. When these particles reach the Earth, they interact with the magnetic field that surrounds the planet. This interaction causes the magnetic field to distort and weaken, which in turn leads to the strange behavior of the aurora borealis and other natural phenomena. As an <a href="https://www.researchgate.net/profile/David-Wallace-29">electrical engineer</a> who specializes in the power grid, I study how geomagnetic storms also threaten to cause power and internet outages and how to protect against that.</p>
<h2>Geomagnetic storms</h2>
<p>The Carrington Event of 1859 is the largest recorded account of a geomagnetic storm, but it is not an isolated event. </p>
<p>Geomagnetic storms have been recorded since the early 19th century, and scientific data from Antarctic ice core samples has shown evidence of an even more massive geomagnetic storm that <a href="https://doi.org/10.1038/nature11123">occurred around A.D. 774</a>, now known as the Miyake Event. That solar flare produced the largest and fastest rise in carbon-14 ever recorded. Geomagnetic storms trigger high amounts of cosmic rays in Earth’s upper atmosphere, which in turn produce <a href="https://www.radiation-dosimetry.org/what-is-carbon-14-production-properties-decay-definition/">carbon-14</a>, a radioactive isotope of carbon.</p>
<p>A geomagnetic storm 60% smaller than the Miyake Event <a href="https://doi.org/10.1038/ncomms2783">occurred around A.D. 993</a>. Ice core samples have shown evidence that large-scale geomagnetic storms with similar intensities as the Miyake and Carrington events occur at an average rate of once every 500 years.</p>
<p>Nowadays the National Oceanic and Atmospheric Administration uses the <a href="https://www.swpc.noaa.gov/noaa-scales-explanation">Geomagnetic Storms scale</a> to measure the strength of these solar eruptions. The “G scale” has a rating from 1 to 5 with G1 being minor and G5 being extreme. The Carrington Event would have been rated G5. </p>
<p>It gets even scarier when you compare the Carrington Event with the Miyake Event. Scientist were able to estimate the strength of the Carrington Event <a href="https://doi.org/10.1007/s11207-005-4980-z">based on the fluctuations of Earth’s magnetic field</a> as recorded by observatories at the time. There was no way to measure the magnetic fluctuation of the Miyake event. Instead, scientists measured the increase in carbon-14 in tree rings from that time period. The Miyake Event produced a <a href="https://doi.org/10.1038/nature11123">12% increase in carbon-14</a>. By comparison, the Carrington Event produced less than 1% increase in Carbon-14, so the Miyake Event likely dwarfed the G5 Carrington Event.</p>
<h2>Knocking out power</h2>
<p>Today, a geomagnetic storm of the same intensity as the Carrington Event would affect far more than telegraph wires and could be catastrophic. With the ever-growing dependency on electricity and emerging technology, any disruption could lead to trillions of dollars of monetary loss and risk to life dependent on the systems. The storm would affect <a href="https://www.cnet.com/science/we-arent-ready-for-a-solar-storm-smackdown/">a majority of the electrical systems</a> that people use every day.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/JncTCE2NWgc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The National Weather Service operates the Space Weather Prediction Center, which watches for solar flares that could lead to geomagnetic storms.</span></figcaption>
</figure>
<p>Geomagnetic storms generate induced currents, which flow through the electrical grid. The geomagnetically <a href="https://www.electricalclassroom.com/what-is-induced-current/">induced currents</a>, which can be in excess of 100 amperes, flow into the electrical components connected to the grid, such as transformers, relays and sensors. One hundred amperes is equivalent to the electrical service provided to many households. Currents this size can cause internal damage in the components, leading to large scale power outages.</p>
<p>A geomagnetic storm three times smaller than the Carrington Event occurred in Quebec, Canada, in March 1989. The storm <a href="https://www.nasa.gov/topics/earth/features/sun_darkness.html">caused the Hydro-Quebec electrical grid to collapse</a>. During the storm, the high magnetically induced currents damaged a transformer in New Jersey and tripped the grid’s circuit breakers. In this case, the outage led to <a href="https://doi.org/10.1038/484311a">five million people being without power for nine hours</a>.</p>
<h2>Breaking connections</h2>
<p>In addition to electrical failures, communications would be disrupted on a worldwide scale. Internet service providers could go down, which in turn would take out the ability of different systems to communicate with each other. High-frequency communication systems such as ground-to-air, shortwave and ship-to-shore radio would be disrupted. Satellites in orbit around the Earth could be damaged by induced currents from the geomagnetic storm burning out their circuit boards. This would lead to <a href="https://www.cnet.com/science/we-arent-ready-for-a-solar-storm-smackdown/">disruptions</a> in satellite-based telephone, internet, radio and television.</p>
<p>[<em>Get fascinating science, health and technology news.</em> <a href="https://memberservices.theconversation.com/newsletters/?nl=science&source=inline-science-fascinating">Sign up for The Conversation’s weekly science newsletter</a>.]</p>
<p>Also, as geomagnetic storms hit the Earth, the increase in solar activity causes the atmosphere to expand outward. This expansion changes the density of the atmosphere where satellites are orbiting. Higher density atmosphere <a href="https://theconversation.com/solar-storms-can-destroy-satellites-with-ease-a-space-weather-expert-explains-the-science-177510">creates drag</a> on a satellite, which slows it down. And if it isn’t maneuvered to a higher orbit, it can fall back to Earth.</p>
<p>One other area of disruption that would potentially affect everyday life is navigation systems. Virtually every mode of transportation, from cars to airplanes, use GPS for navigation and tracking. Even handheld devices such as cell phones, smart watches and tracking tags rely on GPS signals sent from satellites. Military systems are heavily dependent on GPS for coordination. Other military detection systems such as over-the-horizon radar and submarine detection systems could be disrupted, which would hamper national defense.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A crew works on a machine with a giant spool laying a cable in the water" src="https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=369&fit=crop&dpr=1 600w, https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=369&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=369&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=464&fit=crop&dpr=1 754w, https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=464&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/452924/original/file-20220317-22992-qysj2x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=464&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 global internet is held together by a network of cables crisscrossing the world’s oceans.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/germany-mecklenburg-western-pomerania-baltic-sea-undersea-news-photo/548151689">Jens Köhler/ullstein bild via Getty Images</a></span>
</figcaption>
</figure>
<p>In terms of the internet, a geomagnetic storm on the scale of the Carrington Event could <a href="https://dl.acm.org/doi/10.1145/3452296.3472916">produce geomagnetically induced currents in the submarine and terrestrial cables</a> that form the backbone of the internet as well as the data centers that store and process everything from email and text messages to scientific data sets and artificial intelligence tools. This would potentially disrupt the entire network and prevent the servers from connecting to each other.</p>
<h2>Just a matter of time</h2>
<p>It is only a matter of time before the Earth is hit by another geomagnetic storm. A Carrington Event-size storm would be <a href="https://www.swpc.noaa.gov/sites/default/files/images/u33/finalBoulderPresentation042611%20%281%29.pdf">extremely damaging</a> to the electrical and communication systems worldwide with outages lasting into the weeks. If the storm is the size of the Miyake Event, the results would be catastrophic for the world with potential outages lasting months if not longer. Even with <a href="https://www.weather.gov/safety/space-ww">space weather warnings</a> from NOAA’s Space Weather Prediction Center, the world would have only a few minutes to a few hours notice.</p>
<p>I believe it is critical to continue researching ways to protect electrical systems against the effects of geomagnetic storms, for example by <a href="https://www.pnnl.gov/main/publications/external/technical_reports/PNNL-21033.pdf">installing devices that can shield vulnerable equipment</a> like transformers and by developing strategies for adjusting grid loads when solar storms are about to hit. In short, it’s important to work now to minimize the disruptions from the next Carrington Event.</p><img src="https://counter.theconversation.com/content/177982/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Wallace 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>Every few centuries the sun blasts the Earth with a huge amount of high-energy particles. If it were to happen today, it would wreak havoc on technology.David Wallace, Assistant Clinical Professor of Electrical Engineering, Mississippi State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1775102022-03-02T13:28:17Z2022-03-02T13:28:17ZSolar storms can destroy satellites with ease – a space weather expert explains the science<figure><img src="https://images.theconversation.com/files/448971/original/file-20220228-13-1r7fc0y.jpg?ixlib=rb-1.1.0&rect=0%2C42%2C4096%2C4046&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Sun occasionally ejects large amounts of energy and particles into space that can smash into Earth.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Coronal_mass_ejection_erupts_on_the_Sun,_31_August_2012.jpg#/media/File:Coronal_mass_ejection_erupts_on_the_Sun,_31_August_2012.jpg">NASA/GSFC/SDO via WikimediaCommons</a></span></figcaption></figure><p>On Feb. 4, 2022, SpaceX launched 49 satellites as part of Elon Musk’s Starlink internet project, <a href="https://www.cnbc.com/2022/02/09/spacex-losing-starlink-satellites-due-to-geomagnetic-space-storm.html">most of which burned up in the atmosphere days later</a>. The cause of this more than <a href="https://www.cnbc.com/2022/02/09/spacex-losing-starlink-satellites-due-to-geomagnetic-space-storm.html">US$50 million</a> failure was a geomagnetic storm caused by the Sun. </p>
<p>Geomagnetic storms occur when space weather hits and interacts with the Earth. Space weather is caused by fluctuations within the Sun that blast electrons, protons and other particles into space. <a href="https://scholar.google.com/citations?user=TdViV_sAAAAJ&hl=en&oi=ao">I study the hazards space weather poses to space-based assets</a> and how scientists can improve the models and prediction of space weather to protect against these hazards. </p>
<p>When space weather reaches Earth, it triggers many complicated processes that can cause a lot of trouble for anything in orbit. And engineers like me are working to better understand these risks and defend satellites against them.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/lOgIrDirDYY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Sun occasionally blasts huge amounts of particles into space during active events like solar flares and coronal mass ejections.</span></figcaption>
</figure>
<h2>What causes space weather?</h2>
<p>The Sun is always releasing a steady amount of charged particles into space. This is called the solar wind. Solar wind also carries with it the solar magnetic field. Sometimes, localized fluctuations on the Sun will <a href="https://www.swpc.noaa.gov/phenomena/solar-wind">hurl unusually strong bursts of particles in a particular direction</a>. If Earth happens to be in the path of the enhanced solar wind generated by one of these events and gets hit, you get a geomagnetic storm.</p>
<p>The two most common causes of geomagnetic storms are <a href="https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections">coronal mass ejections</a> – explosions of plasma from the surface of the Sun – and <a href="https://www.swpc.noaa.gov/news/coronal-hole-high-speed-streams-ch-hss">solar wind that escapes through coronal holes</a> – spots of low density in the Sun’s outer atmosphere.</p>
<p>The speed at which the ejected plasma or solar wind arrives at Earth is an important factor – the faster the speed, the stronger the geomagnetic storm. Normally, <a href="https://pwg.gsfc.nasa.gov/istp/nicky/cme-chase.html#:%7E:text=Near%20solar%20activity%20maximum%2C%20the,about%20400%20kilometers%20per%20second">solar wind travels at roughly 900,000 mph</a> (1.4 million kph). But strong solar events can release winds up to five times as fast.</p>
<p>The strongest geomagnetic storm on record was caused by a <a href="https://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event">coronal mass ejection in September 1859</a>. When the mass of particles hit Earth, they caused electrical surges in telegraph lines that shocked operators and, in some extreme cases, <a href="https://doi.org/10.1016/j.asr.2006.01.013">actually set telegraph instruments on fire</a>. Research suggests that if a geomagnetic storm of this magnitude hit Earth today, it would cause roughly <a href="https://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event">$2 trillion in damage</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A drawing showing the Earth surrounded by a magnetic field with solar energy compressing one side." src="https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=328&fit=crop&dpr=1 600w, https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=328&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=328&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=412&fit=crop&dpr=1 754w, https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=412&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/448952/original/file-20220228-15-qnx8er.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=412&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 Earth’s magnetic field acts as a shield that absorbs most solar wind.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Magnetosphere_rendition.jpg#/media/File:Magnetosphere_rendition.jpg">NASA via WikimediaCommons</a></span>
</figcaption>
</figure>
<h2>A magnetic shield</h2>
<p>Emissions from the Sun, including the solar wind, would be incredibly dangerous to any life form unlucky enough to be directly exposed to them. Thankfully, Earth’s magnetic field does a lot to protect humanity.</p>
<p>The first thing solar wind hits as it approaches Earth is the magnetosphere. This region surrounding the Earth’s atmosphere is filled with plasma made of electrons and ions. It’s dominated by the planet’s strong magnetic field. When solar wind hits the magnetosphere, it transfers mass, energy and momentum into this layer. </p>
<p>The magnetosphere can absorb most of the energy from the everyday level of solar wind. But during strong storms, it can get overloaded and transfer excess energy to the upper layers of Earth’s atmosphere near the poles. This redirection of energy to the poles is what <a href="https://www.swpc.noaa.gov/phenomena/aurora">results in fantastic aurora events</a>, but it also causes changes in the upper atmosphere that can harm space assets.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing the many layers of the atmosphere: the troposphere, from 0 to 12 km from Earth's surface, moving upward through the stratosphere, mesosphere, thermosphere and finally the exosphere, the layer from 700 to 190,000 km above Earth." src="https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=500&fit=crop&dpr=1 600w, https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=500&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=500&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=628&fit=crop&dpr=1 754w, https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=628&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/449002/original/file-20220228-15-1ec6d9h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=628&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 different layers of Earth’s atmosphere are all affected by solar storms differently.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/cartoon-atmosphere-layers-card-poster-royalty-free-illustration/1064199092?adppopup=true">Bigmouse108 / iStock via Getty Images</a></span>
</figcaption>
</figure>
<h2>Dangers to what’s in orbit</h2>
<p>There a few different ways geomagnetic storms threaten orbiting satellites that serve people on the ground daily.</p>
<p>When the atmosphere absorbs energy from magnetic storms, it heats up and expands upward. This <a href="https://doi.org/10.1029/2005JA011274">expansion significantly increases the density of the thermosphere</a>, the layer of the atmosphere that extends from about 50 miles (80 kilometers) to roughly 600 miles (1,000 km) above the surface of the Earth. Higher density means <a href="https://www.swpc.noaa.gov/impacts/satellite-drag#:%7E:text=The%20drag%20force%20on%20satellites,were%20previously%20at%20lower%20altitudes">more drag, which can be a problem for satellites</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A satellite carrying a stack of Starlink satellites." src="https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/448968/original/file-20220228-13-1wlbbd7.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"></a>
<figcaption>
<span class="caption">Starlink satellites are released in batches, and 40 were destroyed in early February because of a geomagnetic storm.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Starlink_Mission_(47926144123).jpg#/media/File:Starlink_Mission_(47926144123).jpg">SpaceX via WikimediaCommons</a></span>
</figcaption>
</figure>
<p>This situation is exactly what led to the demise of the the SpaceX Starlink satellites in February. Starlink satellites are <a href="https://www.cnbc.com/2022/02/09/spacex-losing-starlink-satellites-due-to-geomagnetic-space-storm.html">dropped off by Falcon 9 rockets into a low-altitude orbit</a>, typically somewhere between 60 and 120 miles (100 and 200 km) above the Earth’s surface. The satellites then use onboard engines to slowly overcome the force of drag and raise themselves to their final altitude of approximately <a href="https://www.cnbc.com/2022/02/09/spacex-losing-starlink-satellites-due-to-geomagnetic-space-storm.html">350 miles (550 km)</a>. </p>
<p>The latest batch of Starlink satellites encountered a geomagnetic storm while still in very low-Earth orbit. Their engines could not overcome the <a href="https://www.cnbc.com/2022/02/09/spacex-losing-starlink-satellites-due-to-geomagnetic-space-storm.html">significantly increased drag</a>, and the satellites began slowly falling toward Earth and eventually burned up in the atmosphere.</p>
<p>Drag is just one hazard that space weather poses to space-based assets. The significant increase in high-energy electrons within the magnetosphere during strong geomagnetic storms means more electrons will penetrate the shielding on a spacecraft and accumulate within its electronics. This buildup of electrons can <a href="https://www.nasa.gov/vision/universe/solarsystem/killer_electrons.html">discharge in what is basically a small lightning strike</a> and damage electronics. </p>
<p>Penetrating radiation or charged particles in the magnetosphere – even during mild geomagnetic storms – can also <a href="https://www.cambridge.org/core/books/spacecraftenvironment-interactions/F722691656610F887D25CB66695DDE01#:%7E:text=Spacecraft%2DEnvironment%20Interactions%20is%20a,and%20for%20spacecraft%20system%20engineers">alter the output signal from electronic devices</a>. This phenomenon can cause errors in any part of a spacecraft’s electronics system, and if the error occurs in something critical, the entire satellite can fail. Small errors are common and usually fixable, but <a href="https://doi.org/10.1002/swe.20023">total failures, though rare, do happen</a>.</p>
<p>Finally, geomagnetic storms can disrupt the ability of satellites to communicate with Earth using radio waves. Many communications technologies, like GPS, for example, <a href="https://www.sciencedirect.com/topics/social-sciences/radio-waves#:%7E:text=GPS%20receivers%20use%20radio%20waves,a%20reference%20system%20for%20GPS.">rely on radio waves</a>. The atmosphere always <a href="https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6431636">distorts radio waves by some amount </a>, so engineers correct for this distortion when building communication systems. But during geomagnetic storms, changes in the ionosphere – the charged equivalent of the thermosphere that spans roughly the same altitude range – will change how radio waves travel through it. The calibrations in place for a quiet atmosphere become wrong during geomagnetic storms.</p>
<p>This, for example, makes it difficult to lock onto GPS signals and can <a href="https://doi.org/10.1029/2018SW001940">throw off the positioning by a few meters</a>. For many industries – aviation, maritime, robotics, transportation, farming, military and others – GPS positioning errors of a few meters are simply not tenable. Autonomous driving systems will require accurate positioning as well.</p>
<h2>How to protect against space weather</h2>
<p>Satellites are critically important for much of the modern world to function, and protecting space assets from space weather is an <a href="https://www.sworm.gov/">important area of research</a>. </p>
<p>Some of the risks can be minimized by <a href="https://doi.org/10.1038/s41598-021-99739-2">shielding electronics from radiation</a> or <a href="https://doi.org/10.1016/j.actaastro.2020.12.010">developing materials</a> that are more resistant to radiation. But there is only so much shielding that can be done in the face of a <a href="https://doi.org/10.1038/s41598-021-99739-2">powerful geomagnetic storm</a>.</p>
<p>[<em>Over 140,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140ksignup">Sign up today</a>.]</p>
<p>The ability to accurately forecast storms would make it possible to preemptively safeguard satellites and other assets to a certain extent by shutting down sensitive electronics or reorienting the satellites to be better protected. But while the modeling and forecasting of geomagnetic storms has significantly improved over the past few years, the projections are often wrong. The National Oceanic and Atmospheric Administration had warned that, following a coronal mass ejection, a <a href="https://www.space.com/sunspot-ar2936-solar-flare-cme-arrival-earth">geomagnetic storm was “likely” to occur</a> the day before or the day of the February Starlink launch. The mission went ahead anyway.</p>
<p>The Sun is like a child that often throws tantrums. It’s essential for life to go on, but its ever-changing disposition make things challenging.</p><img src="https://counter.theconversation.com/content/177510/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Piyush Mehta receives funding from the National Science Foundation and the National Aeronautics and Space Administration. He is affiliated with the National Aeronautics and Space Administration as a Special Government Employee and is a member of the NASA Space Weather Council. </span></em></p>Space weather can affect satellites in a number of different ways, from frying electronics to increasing drag in the atmosphere.Piyush Mehta, Assistant Professor of Mechanical and Aerospace Engineering, West Virginia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1598952021-05-05T15:52:51Z2021-05-05T15:52:51ZSpace weather is difficult to predict — with only an hour to prevent disasters on Earth<figure><img src="https://images.theconversation.com/files/397967/original/file-20210429-19-3t3kvx.jpg?ixlib=rb-1.1.0&rect=7%2C39%2C5250%2C6535&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The interaction of solar winds and the Earth’s atmosphere produces the northern lights that dance across the night sky. </span> <span class="attribution"><span class="source">(Benjamin Suter/Unsplash)</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Recent developments at the forefront of astronomy allow us to observe that <a href="https://www.cnn.com/2021/04/13/world/raindrops-other-planets-scn/index.html">planets orbiting other stars have weather</a>. Indeed, we have known that other planets in our own solar system have weather, in many cases more extreme than our own. </p>
<p>Our lives are affected by short-term atmospheric variations of weather on Earth, and we fear that longer-term climate change will also have a large impact. The recently coined term “space weather” refers to effects that arise in space but affect Earth and regions around it. More subtle than meteorological weather, space weather usually acts on technological systems, and has potential impacts that range from communication disruption to power grid failures.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/solar-weather-has-real-material-effects-on-earth-118453">Solar weather has real, material effects on Earth</a>
</strong>
</em>
</p>
<hr>
<p>An ability to predict space weather is an essential tool in providing warnings so that mitigation can be attempted, and to hopefully, in extreme cases, forestall a disaster. </p>
<h2>The history of weather forecasting</h2>
<p>We are now used to large-scale meteorological forecasts that are quite accurate for about a two-week timescale. </p>
<p>Scientific weather forecasting originated about a century ago, with the term <a href="https://www.smithsonianmag.com/history/how-world-war-i-changed-weather-good-180963360/">“front” being associated with the First World War</a>. Meteorological prediction is based on a good knowledge of underlying theory, codified into massive computer programs running on the most advanced computers, with huge amounts of input data. </p>
<p>Important aspects of weather, like moisture content, can be measured by satellites that monitor continuously. Other measurements are also be readily taken, for example, by the nearly 2,000 weather balloons launched each day. Exploring the limits in weather forecasting gave rise to chaos theory, sometimes called the “butterfly effect.” The buildup of error brings about the two-week practical limit. </p>
<p>In contrast, the prediction of space weather is only truly reliable about one hour in advance!</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/fDek6cYijxI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An explainer of the science behind chaos.</span></figcaption>
</figure>
<h2>Solar effects</h2>
<p>Most space weather <a href="https://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html">originates from the sun</a>. Its outermost atmosphere blows into space at supersonic speeds, although at such low density that interplanetary space is more rarified than what is considered a vacuum in our laboratories. Unlike winds on Earth, this solar wind carries along a magnetic field. This is much smaller than Earth’s own field that we can detect with a compass at the surface, and vastly smaller than that near a fridge magnet, but it can interact with Earth, with an important role in space weather. </p>
<p>The very thin solar wind, with a very weak magnetic field, can nevertheless affect Earth in part because it interacts with a large magnetic bubble around Earth, called the magnetosphere, over a very large area, at least a hundred times as big as the surface of our planet. Much like a breeze that can barely move a thread can move a huge sailing ship when caught on the large sails, the effect of solar wind, through its direct pressure (like on a sail) or through its magnetic field interacting with Earth’s, can be enormous. </p>
<p>As the origin point, the sun itself is a seething mass of hot gas and magnetic fields, and their interaction is complex, sometimes even explosive. Magnetic fields are concentrated near sunspots, and <a href="https://earthobservatory.nasa.gov/world-of-change/Solar">produce electromagnetic phenomena like solar flares (the name says it all) and coronal mass ejections</a>. Much as with tornadoes on Earth, we know generally when conditions are favourable for these localized explosions, but precise prediction is difficult. </p>
<p>Even once an event is detected, if a large mass of fast, hot and dense gas is shot in our direction (and such a “cloud” in turn is difficult to detect, coming at us against the glare of the sun), there is a further complicating factor in predicting its danger.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/8OcqH_l6Mso?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA scientists answer questions about space weather.</span></figcaption>
</figure>
<h2>Detecting magnetic fields</h2>
<p>Unlike the detectable, sometimes even visible, water content in the atmosphere that is so important in meteorology, the magnetic field of gas ejected from the sun, including in hot and denser clouds from explosions, is almost impossible to detect from afar. The effect of an interplanetary cloud is greatly enhanced if the direction of its magnetic field is opposite to Earth’s own field where it hits the barrier of Earth’s magnetosphere. In that case, a process known as “reconnection” allows much of the cloud’s energy to be transferred to the region near Earth, and accumulate largely on the night side, despite the cloud hitting on the side facing the sun. </p>
<p>By secondary processes, usually involving further reconnection, this energy produces space weather effects. Earth’s <a href="https://www.space.com/33948-van-allen-radiation-belts.html">radiation belts can be greatly energized</a>, endangering astronauts and even satellites. These processes can also produce bright auroras, whose beauty hides danger since they in turn produce magnetic fields. A generator effect takes place when dancing auroras make magnetic fields vary, but unlike in the generators that produce much of our electricity, the electric fields from auroras are uncontrolled. </p>
<p>The electric fields from auroras are small, and undetectable to human senses. However, over a very large region they can build up to apply a considerable voltage. It’s this effect that poses a hazard to our largest infrastructure, such as electric grids. To predict when this might happen, we would need to measure from afar the size and direction of magnetic field in an incoming space cloud. However, that invisible field is stealthy and hard to detect until it is nearly upon us.</p>
<h2>Satellite monitors</h2>
<p>By the gravitational laws of orbits, a satellite continuously monitoring magnetic fields by direct measurement must sit about a million miles (1.6 million kilometres) from Earth, between us and the sun a hundred times further away. A magnetic cloud causing minor space weather effects usually takes about three days to come from the sun to Earth. A truly dangerous cloud, from a bigger solar explosion, may take as little as a day. Since our monitoring satellites are relatively close to Earth, we only know about the crucial magnetic field direction at most one hour in advance of impact. This is not much time to prepare vulnerable infrastructure, like power and communication networks and satellites, to best survive.</p>
<p>Since the fleets of satellites needed to give better warning are not even on the drawing boards, we must rely on luck in the face of space weather. It may be a small comfort that the coming solar maximum — when the surface of the sun is at its most active during a cycle and is expected to peak in 2025 — <a href="https://www.nasa.gov/press-release/solar-cycle-25-is-here-nasa-noaa-scientists-explain-what-that-means">is predicted to be mild</a>. </p>
<p>It may be Mark Twain who said “it is hard to make predictions, especially about the future,” but it is certainly true in the case of space weather.</p><img src="https://counter.theconversation.com/content/159895/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Gerard Connors receives funding from NSERC, the Canada Foundation for Innovation, Alberta Innovation, and the Canadian Space Agency. </span></em></p>It has only been in the past century that weather prediction on Earth has advanced enough to work two weeks in advance. Predicting space weather, however, is only reliable an hour in advance.Martin Connors, Professor of Space Science and Physics, Athabasca UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1599912021-05-03T12:03:31Z2021-05-03T12:03:31ZMassive flare seen on the closest star to the solar system: What it means for chances of alien neighbors<figure><img src="https://images.theconversation.com/files/397916/original/file-20210429-21-qm3fki.jpg?ixlib=rb-1.1.0&rect=32%2C70%2C1230%2C1153&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Proxima Centauri is the closest star to the solar system and is home to a potentially habitable planet.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:New_shot_of_Proxima_Centauri,_our_nearest_neighbour_(10581847073).jpg#/media/File:New_shot_of_Proxima_Centauri,_our_nearest_neighbour_(10581847073).jpg">Hubble/European Space Agency/WikimediaCommons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>The Sun isn’t the only star to produce stellar flares. On April 21, 2021, a team of astronomers published new research describing the <a href="https://doi.org/10.3847/2041-8213/abf14c">brightest flare ever measured from Proxima Centauri in ultraviolet light</a>. To learn about this extraordinary event – and what it might mean for any life on the planets orbiting Earth’s closest neighboring star – The Conversation spoke with <a href="https://scholar.google.com/citations?user=I-dkA7UAAAAJ&hl=en&oi=ao">Parke Loyd, an astrophysicist at Arizona State University</a> and co-author of the paper. Excerpts from our conversation are below and have been edited for length and clarity.</em></p>
<h2>Why were you looking at Proxima Centauri?</h2>
<p>Proxima Centauri is the closest star to this solar system. A couple of years ago, <a href="https://doi.org/10.1038/nature19106">a team discovered</a> that there is a <a href="https://exoplanets.nasa.gov/exoplanet-catalog/7167/proxima-centauri-b/">planet – called Proxima b – orbiting the star</a>. It’s just a little bit bigger than Earth, <a href="https://doi.org/10.1038/nature19106">it’s probably rocky</a> and it is in what is called the habitable zone, or the Goldilocks zone. This means that Proxima b is about the right distance from the star so that it could have liquid water on its surface.</p>
<p>But this star system differs from the Sun in a pretty key way. Proxima Centauri is a small star called a <a href="https://www.space.com/23772-red-dwarf-stars.html">red dwarf</a> – it’s around 15% of the radius of our Sun, and it’s substantially cooler. So Proxima b, in order for it to be in that Goldilocks zone, actually is a lot closer to Proxima Centauri than Earth is to the Sun. </p>
<p>You might think that a smaller star would be a tamer star, but that’s actually not the case at all – red dwarfs produce stellar flares <a href="https://ui.adsabs.harvard.edu/abs/1989MmSAI..60..263G/abstract">a lot more frequently than the Sun does</a>. So Proxima b, the closest planet in another solar system with a chance for having life, is subject to space weather that is a lot more violent than the space weather in Earth’s solar system.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of the surface of the Sun with a towering explosion of plasma." src="https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=601&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=601&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=601&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=756&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=756&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397919/original/file-20210429-15-1b7x9r9.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=756&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 flares – like this one captured by a NASA satellite orbiting the Sun – eject huge amounts of radiation.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Solar_flare_(TRACE).gif#/media/File:Solar_flare_(TRACE).gif">NASA/Wikimedia Commons</a></span>
</figcaption>
</figure>
<h2>What did you find?</h2>
<p>In 2018, my colleague Meredith MacGregor discovered flashes of light coming from Proxima Centauri that <a href="https://doi.org/10.3847/2041-8213/aaad6b">looked very different from solar flares</a>. She was using a telescope that detects light at millimeter wavelengths to monitor Proxima Centauri and saw a big of flash of light in this wavelength. Astronomers had never seen a stellar flare in millimeter wavelengths of light.</p>
<p>My colleagues and I wanted to learn more about these unusual brightenings in the millimeter light coming from the star and see whether they were actually flares or some other phenomenon. We used nine telescopes on Earth, as well as a satellite observatory, to get the longest set of observations – about two days’ worth – of Proxima Centauri with the most wavelength coverage that had ever been obtained.</p>
<p>Immediately we <a href="https://doi.org/10.3847/2041-8213/abf14c">discovered a really strong flare</a>. The ultraviolet light of the star increased by over 10,000 times in just a fraction of a second. If humans could see ultraviolet light, it would be like being blinded by the flash of a camera. Proxima Centauri got bright really fast. This increase lasted for only a couple of seconds, and then there was a gradual decline.</p>
<p>This discovery confirmed that indeed, these weird millimeter emissions are flares.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A gray rocky planet with a pale star behind it." src="https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397922/original/file-20210429-19-9tx3mg.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"></a>
<figcaption>
<span class="caption">Proxima b – shown here in an artist’s rendering – is rocky and might support water or even life if the atmosphere is still intact.</span>
<span class="attribution"><a class="source" href="https://www.eso.org/public/images/ann16056a/">European Southern Observatory/M. Kornmesser</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>What does that mean for chances of life on the planet?</h2>
<p>Astronomers are actively exploring this question at the moment because it can kind of go in either direction. When you hear ultraviolet radiation, you’re probably thinking about the fact that people wear sunscreen to try to protect ourselves from ultraviolet radiation here on Earth. Ultraviolet radiation can <a href="https://www.livescience.com/38039-what-causes-sunburns.html">damage proteins and DNA</a> in human cells, and this results in sunburns and can cause cancer. That would potentially be true for life on another planet as well. </p>
<p>On the flip side, messing with the chemistry of biological molecules can have its advantages – it <a href="https://doi.org/10.1023/A:1006596718708">could help spark life on another planet</a>. Even though it might be a more challenging environment for life to sustain itself, it might be a better environment for life to be generated to begin with.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>But the thing that astronomers and astrobiologists are most concerned about is that every time one of these huge flares occurs, it basically <a href="https://doi.org/10.1089/ast.2017.1794">erodes away a bit of the atmosphere</a> of any planets orbiting that star – including this potentially Earth-like planet. And if you don’t have an atmosphere left on your planet, then you definitely have a pretty hostile environment to life – there would be huge amounts of radiation, massive temperature fluctuations and little or no air to breathe. It’s not that life would be impossible, but having the surface of a planet basically directly exposed to space would be an environment totally different than anything on Earth.</p>
<h2>Is there any atmosphere left on Proxima b?</h2>
<p>That’s anybody’s guess at the moment. The fact that these flares are happening doesn’t bode well for that atmosphere being intact – especially if they’re associated with <a href="https://doi.org/10.1146/annurev.aa.07.090169.001053">explosions of plasma</a> like what happens on the Sun. But that’s why we’re doing this work. We hope the folks who build models of planetary atmospheres can take what our team has learned about these flares and try to figure out the odds for an atmosphere being sustained on this planet.</p><img src="https://counter.theconversation.com/content/159991/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>R. O. Parke Loyd receives funding from NASA. </span></em></p>Astronomers just measured the largest flare ever from Proxima Centauri, humanity’s closest neighboring star. These flares could be bad news for life trying to develop on a planet orbiting the star.R. O. Parke Loyd, Post-Doctoral Researcher in Astrophysics, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1576302021-03-29T11:12:26Z2021-03-29T11:12:26ZWhy we need to get better at predicting space weather<figure><img src="https://images.theconversation.com/files/391681/original/file-20210325-19-cp881k.jpg?ixlib=rb-1.1.0&rect=155%2C116%2C6334%2C3327&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A solar flare.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/sun-solar-flare-particles-coronal-mass-752393257">Shutterstock/Color4260</a></span></figcaption></figure><p>The Sun is the most important source of energy for sustaining life on Earth, but it gives us a lot more than just light and heat. It also gives us solar storms. </p>
<p>Disturbances on the Sun, such as coronal mass ejections produced by solar flares that emanate from active sunspot regions, can cause solar storms. Solar flares and coronal mass ejections emit vast quantities of radiation and charged particles into space. </p>
<p>These events can damage the Earth’s <a href="https://theconversation.com/solar-storms-could-lead-to-a-global-techno-meltdown-16678">communication and power infrastructures</a>, resulting in power outages and reduced system functionality. Satellites, space stations and astronauts, aviation, GPS, power grids and more can be affected.</p>
<p>As our civilisation becomes more advanced, we become more vulnerable to the effects of solar storms. Now, as the Sun’s activity <a href="https://www.esa.int/Safety_Security/Solar_cycle_25_the_Sun_wakes_up">is on the increase</a>, we need to get better at predicting solar weather.</p>
<p>Many people still remember the collapse of Canada’s Quebec electrical grid on <a href="https://www.nasa.gov/topics/earth/features/sun_darkness.html">13 March 1989</a>, which lasted for nine hours and affected six million people. It caused hundreds of millions of dollars in damages and lost revenues. This blackout was caused by solar storms. </p>
<p><a href="https://www.swsc-journal.org/articles/swsc/pdf/2013/01/swsc130015.pdf">The Carrington Event</a>, named for the amateur astronomer who recorded it, was another powerful solar storm which happened in September 1859. Cutting edge technology in 1859 was limited to electrical telegraphs, and most of those failed all over Europe and North America, in some cases giving their operators electric shocks. </p>
<p>These days, we’re much more reliant on technology, which is in turn increasingly vulnerable to the effects of space and its unique natural disasters.</p>
<h2>Space radiation</h2>
<p>Space is vast, cold, dark and awash with radiation. Radiation in space comes mainly from galactic cosmic radiation – high energy particles thrown out from other galaxies – and solar particle events – high energy particles from our own Sun.</p>
<p>In space radiation, atoms are accelerated in interstellar space to speeds close to the speed of light. Eventually, the electrons are stripped out and only the positively charged nucleus remains.</p>
<p>Humans have been observing and counting sunspots for more than 400 years, making this the <a href="https://www.nature.com/news/long-term-research-slow-science-1.12623#:%7E:text=The%20world's%20longest%2Drunning%20experiments,a%20marathon%2C%20not%20a%20sprint.&text=Although%20science%20is%20a%20long,length%20of%20a%20funding%20cycle.">longest running experiment</a> in the world. The sun has an 11-year sunspot cycle, and at the moment, we are in the middle of that cycle. Now it’s approaching “solar maximum”, where the greatest solar activity occurs. The next solar maximum is expected to begin in 2025.</p>
<figure class="align-center ">
<img alt="The northern lights over a lake." src="https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.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">
<figcaption>
<span class="caption">The northern lights are caused by solar flares.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/icelandic-spiral-northern-lights-autumn-time-528933889">Shutterstock/Mike-Hubert.com</a></span>
</figcaption>
</figure>
<p>People are familiar with the northern lights, which is one visible effect of solar radiation. Earth’s magnetic field, which protects us from most of the dangers of space radiation, directs the charged particles to the poles, where they enter our atmosphere and cause beautiful light displays.</p>
<p>But the radiation can also impact technology and people. During strong solar radiation storms, energetic protons can damage electronic circuits inside satellites and the biological DNA of astronauts. Passengers and crew flying over the north pole would be exposed to increased radiation. </p>
<p>These radiation storms can create errors that make navigation operations extremely difficult. Energetic protons can also ionise the atoms and molecules in the atmosphere, creating a layer of free electrons. This layer can absorb high-frequency radio waves, causing a blackout of high-frequency communications, also known as shortwave radio.</p>
<p>With our increasing reliance on technology, predicting the weather in space is crucial. However, accurately predicting space weather has long been a challenging problem for experts.</p>
<h2>Predicting space weather</h2>
<p>Understanding the complexity of sunspots will help us predict whether significant solar flares may happen. My colleagues and I developed a real-time automated computer system which uses image processing and artificial intelligence technologies to monitor and analyse solar satellite data. This helps predict the likelihood of solar flares in the coming 24 hours. </p>
<p>We pioneered new techniques for automatic processing, detection and feature extraction of solar features – like active regions and sunspots – captured by Nasa’s solar dynamics observatory satellite. We also introduced the first automated and real-time system <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2008SW000401">to classify sunspots</a>. Before this, the classification of sunspots was a manual process painstakingly carried out by experts. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/four-graphs-that-suggest-we-cant-blame-climate-change-on-solar-activity-130154">Four graphs that suggest we can't blame climate change on solar activity</a>
</strong>
</em>
</p>
<hr>
<p>Space missions and astronauts are much more likely to be affected by radiation, because they aren’t protected by Earth’s magnetic field. The effects on humans could include radiation sickness, increased risk for cancer, degenerative diseases and central nervous system effects. </p>
<p>Despite these risks, human and robotic activities are increasing in space and Nasa is working to land humans on Mars by the 2030s. There are two rovers – <a href="https://theconversation.com/curiosity-catches-a-whiff-of-methane-on-mars-and-a-possibility-of-past-life-35595">Curiosity</a> and <a href="https://theconversation.com/mars-perseverance-rover-set-for-nail-biting-landing-heres-the-rocket-science-154886">Perseverance</a> – and <a href="https://theconversation.com/mars-insight-why-well-be-listening-to-the-landing-of-the-perseverance-rover-153672">one lander</a> currently operational on Mars, with <a href="https://theconversation.com/how-the-exomars-mission-could-sniff-out-life-on-mars-and-what-to-do-next-56182">another rover planned</a> for launch in 2022. </p>
<p>Our space weather prediction system is <a href="http://spaceweather.inf.brad.ac.uk/">publicly available</a>, and is now used as one of the decision-making tools for Nasa’s robotic missions and to manage radiation effects on Nasa’s Chandra X-ray observatory orbit.</p>
<p>As we continue venturing further into space, we’ll need to strengthen our current space weather prediction capabilities to build a greater picture of solar activity and mitigate its effects around the solar system. </p>
<p>This task is incredibly challenging, as most solar observations are taken for Earth’s field of view. Better modelling and investigation of the evolution of solar features is necessary to accommodate for the drastically different celestial orbits around the Sun.</p><img src="https://counter.theconversation.com/content/157630/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rami Qahwaji received funding from The Engineering and Physical Sciences Research Council (EPSRC), European Commission, and the European Space Agency.</span></em></p>Satellites, space stations and astronauts, aviation, GPS, power grids and more can be affected.Rami Qahwaji, Professor of Visual Computing, University of BradfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1374572020-04-30T18:03:21Z2020-04-30T18:03:21ZThe Sun: study shows it’s less active than sibling stars – here’s what that could mean<figure><img src="https://images.theconversation.com/files/331567/original/file-20200429-51457-ll2phm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The sun emitting a sudden flash of light—a solar flare.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>All stars emit varying amounts of light over time – and the Sun is no exception. Such changes in starlight can help us understand how habitable any planets around other stars are – a very active star may bombard its planets with harmful radiation. Now a new study, <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.aay3821">published in Science</a>, shows that the Sun is significantly less active than other, similar stars. </p>
<p>In many stars, the observed variation in brightness is driven by their internal magnetic field. When parts of the magnetic field breaks out through a star’s surface, it can cause dark regions known as <a href="https://aasnova.org/2018/12/12/what-are-starspots-like-on-sun-like-stars/">starspots</a> or brighter regions (known as <a href="https://www.isf.astro.su.se/highlights/faculae-explained/">faculae</a>) in the star’s atmosphere. As a star rotates on its axis, so the bright and dark regions pass across the face of the star from our viewpoint, causing a periodic change in brightness of the star as a result.</p>
<p>Some of the most extreme examples of variable stars are <a href="https://britastro.org/vss/EBHandbook11.pdf">eclipsing binary stars</a> and <a href="https://www.atnf.csiro.au/outreach/education/senior/astrophysics/variable_pulsating.html">pulsating stars</a>. In the former, the light variation is due to an external effect: a pair of stars orbit around their common centre of mass, repeatedly blocking some of their partner’s light from our point of view. If the orbit is viewed edge-on, the brightness of the star will appear to decrease significantly at regular intervals.</p>
<p>In a pulsating star, the light variation has an intrinsic cause: the star literally pulses in and out, becoming larger then smaller, brighter then fainter, with a regularly repeating pattern of changing brightness. Pulsating stars can change in brightness by a factor of ten or more with each cycle. Both of these classes of stars are favourite targets for astronomers, as their light variation may be used to probe the dynamics or structure of a stellar system.</p>
<h2>Calm before the storm?</h2>
<p>The stellar brightness variations due to bright and dark spots rotating across our line of sight are generally of much lower amplitude though. The Sun’s brightness only varies by a fraction of a percent as it rotates once every <a href="https://www.livescience.com/32894-does-the-sun-rotate.html">24 days</a>. Even such small changes can affect the Earth’s climate on timescales of decades or its atmospheric chemistry on timescales as short as months or days. </p>
<p>We have <a href="https://www.space.com/42702-400-years-solar-observations.html">records of sunspots</a> dating back to 1610, and they show that the Sun regularly goes through a cycle every 11 years during which the number of sunspots alternately reach a maximum and then virtually disappear entirely. When sunspots are at their most prevalent, the Sun is particularly active – outbursts of light known as <a href="https://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html">solar flares and coronal mass ejections</a> are more common. These can have significant impact on our lives here on Earth. As well as causing the <a href="https://www.nasa.gov/content/about-auroras">northern lights</a>, they can also disrupt satellites and damage power lines. </p>
<p>In the new study, researchers compared a detailed 140-year record of the Sun’s brightness with the light curves of a set of solar siblings observed by the <a href="https://www.nasa.gov/mission_pages/kepler/overview/index.html">Kepler satellite</a> over the course of four years. They looked at stars whose temperature, mass, radius and age were all similar to the Sun, and selected 349 stars for which the rotation period could be measured as between 20 and 30 days. </p>
<p>The astronomers measured a range of variability from 0 (no change in brightness) to 0.75%, with an average around 0.36%. By taking random four-year segments of the Sun’s light curve, they found the typical variability of the Sun’s brightness was only 0.07% – and even at its greatest was no more than 0.20%. They therefore concluded that most stars of the same type as the Sun are more active than the Sun.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/331566/original/file-20200429-51461-f4gb0f.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">
<figcaption>
<span class="caption">Brightness variations of the Sun in comparison with the star KIC 7849521.</span>
<span class="attribution"><span class="source">MPS / hormesdesign.de</span></span>
</figcaption>
</figure>
<p>So does this mean that the Sun is genuinely different to other stars in the same class? Astronomers know that, as stars age, their <a href="https://www.astrobio.net/cosmic-evolution/gyrochronology/">rotation slows</a> and they become less magnetically active. At some point they may transition to a new phase of very low activity - but we don’t know exactly when that transition occurs. Perhaps the Sun is approaching such a stage in its life. Alternatively, could it simply be that, in the 140 years of solar data used, we have only sampled a relatively quiet period of the Sun’s activity – might it have been more active at other times?</p>
<p>This possibility is more worrying. It might suggest that the Sun could undergo periods when its variability is much higher, with a corresponding increase in magnetic activity and stronger outflows that could disrupt life here on Earth. </p>
<p>Perhaps comfortingly, measurements of certain isotopes – variants of chemical elements with lighter or heavier nuclei – on Earth can be used to <a href="https://www.aanda.org/articles/aa/pdf/2018/12/aa32956-18.pdf">track solar activity</a> over the last 9000 years. They reveal that the variation of the Sun’s brightness has not changed significantly on this timescale either.</p>
<p>Understanding stellar variability is vital for assessing the habitability of exoplanets. In extreme cases, stellar flares may strip the atmosphere from an otherwise habitable exoplanet, rendering it unsuitable for life. The recently discovered planet orbiting the nearest star, <a href="https://theconversation.com/possibly-habitable-planet-found-around-our-nearest-neighbour-star-64321">Proxima b</a>, for example, is in its star’s habitable zone, but Proxima Centauri itself is a very active star and the planet is most likely bathed in harmful radiation from stellar flares.</p>
<p>This new study may indicate that only very inactive stars such as the Sun are likely to host habitable exoplanets. Perhaps we should be grateful that the Sun is among the more sedate of its siblings.</p><img src="https://counter.theconversation.com/content/137457/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Norton 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>Has the Sun entered a stage of old age?Andrew Norton, Professor of Astrophysics Education, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1184532019-07-10T21:23:21Z2019-07-10T21:23:21ZSolar weather has real, material effects on Earth<figure><img src="https://images.theconversation.com/files/283405/original/file-20190709-44487-194iyqg.jpg?ixlib=rb-1.1.0&rect=9%2C0%2C6480%2C3648&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar flares and other phenomena can have a surprising effect on our Earthly activities.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>On Sep. 1, 1859, solar astronomer Richard Carrington <a href="https://science.nasa.gov/science-news/science-at-nasa/2008/06may_carringtonflare">witnessed sunspots that suddenly and briefly flashed brightly before they disappeared</a>. Just before dawn the next day, auroras erupted over most of the Earth, reaching as far south as the Caribbean and Hawaii while southern lights were seen as far north as Chile. The event produced not only a visible light show in areas where they do not typically appear, <a href="https://news.nationalgeographic.com/news/2011/03/110302-solar-flares-sun-storms-earth-danger-carrington-event-science/">but it also sent telegraph systems around the world haywire</a>. </p>
<p>Given the state of technology during Carrington’s time, the impact of a geomagnetic storm was limited to disruptions of telegraph service. If something similar happened today, the world’s technological infrastructure could grind to a halt. Extreme space weather events such as geomagnetic storms are <a href="http://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdf">more disruptive now</a> than in the past. This is because of our greater dependence on technical systems that can be affected by electric currents and energetic particles high in the Earth’s atmosphere.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/nNng0KrNUuI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An active region on the sun — an area of intense and complex magnetic fields — has rotated into view on the sun in this video captured by NASA’s Solar Dynamics Observatory between July 5-11, 2017. The dark core of this sunspot is larger than Earth.</span></figcaption>
</figure>
<h2>The space weather threat</h2>
<p>We might think of space as a silent, empty void and the sun as only a distant source of light and heat. This is not necessarily true. <a href="https://www.huffpost.com/entry/the-unpredictability-of-s_b_9721612">The sun and the Earth are connected in more complex, intimate and sometimes dangerous ways</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-scorching-winds-on-the-surface-of-the-sun-and-how-were-forecasting-them-44098">The scorching winds on the surface of the sun – and how we're forecasting them</a>
</strong>
</em>
</p>
<hr>
<p>Sunspots are <a href="http://swe.ssa.esa.int/what-is-space-weather">temporary phenomena on the sun’s photosphere</a> that appear darker than the surrounding areas. Sunspots can change continuously and may last for only a few hours to days; or even months for the more intense groups. <a href="https://www.swpc.noaa.gov/news/sunspots-and-solar-cycles">The total number of sunspots has long been known to vary with an approximately 11-year repetition known as the solar cycle.</a> The peak of sunspot activity is known as solar maximum and the lull is known as solar minimum. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&rect=9%2C10%2C987%2C775&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&rect=9%2C10%2C987%2C775&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=470&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=470&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=470&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283143/original/file-20190708-51258-3lyq8n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Vivid orange streamers of super-hot, electrically charged gas (plasma) arc from the surface of the sun, revealing the structure of the solar magnetic field rising vertically from a sunspot.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/mission_pages/hinode/news/five-yearsa.html">Hinode, JAXA/NASA</a></span>
</figcaption>
</figure>
<p>Indicating intense magnetic activity, sunspots accompany secondary phenomena such as bursts of electromagnetic radiation (flares) and coronal mass ejections (CME) — which are sudden eruptions of material — accompanied by solar energetic particles (SEPs). A solar flare is a sudden release of energy from the sun, while a CME shoots hot plasma from the sun into space. </p>
<p>The precise mechanisms that trigger flares and CMEs are still being debated, but the bigger the group of sunspots, <a href="https://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html#q8">the more intense solar activity tends to be</a>. The sun continually ejects high-energy electrons, protons and other nuclei that bombard the Earth. <a href="https://www.space.com/11506-space-weather-sunspots-solar-flares-coronal-mass-ejections.html">Solar flares and CMEs send enormous amounts of energy</a> and charged particles hurtling into collision with the Earth’s upper atmosphere, where they can cause geomagnetic storms.</p>
<p>Charged particles during geomagnetic storms cause disturbances in the Earth’s magnetic field, generating effects on electrical systems. <a href="https://doi.org/10.1111/risa.12765">Geomagnetic storms produce numerous effects</a> such as voltage disruptions leading to power outages; changes in soil voltage that enhance corrosion in oil pipelines; disruption in satellite, radio and cellular communications networks; exposure to elevated levels of radiation; and reductions in flights with polar routes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283404/original/file-20190709-44487-kk7r6v.jpeg?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">A solar flare surges off the lower left hand of the sun on Oct. 19, 2014. The image was captured in extreme ultraviolet wavelength of 131 Angstroms – a wavelength that can see the intense heat of a flare and that is typically represented in teal.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/content/goddard/new-sunspot-releases-x11-class-solar-flare">NASA/SDO</a></span>
</figcaption>
</figure>
<p>For the most part, the Earth’s magnetic field protects humans from the barrage of radiation which comes from the sun. However, the Earth’s magnetic field is weaker at either pole and therefore some particles of enter the Earth’s atmosphere through geomagnetic storms. </p>
<h2>Solar weather effects</h2>
<p>The adverse economic impacts of solar activity on the North American power grid have been well-documented. For instance, <a href="https://doi.org/10.1051/swsc/2013041">four per cent of the power disturbances</a> between 1992 and 2010 reported to the U.S. Department of Energy are attributable to strong geomagnetic activity.</p>
<p>I have been working on the <a href="https://ideas.repec.org/p/wis/wpaper/1707.html">economic effects of climate change</a> for some time now and thought: “How about the sun?” </p>
<p>Interestingly, while the study of space weather is a rapidly growing field, academic work to assess its overall social and economic impacts appears to be in its infancy. </p>
<p>I am currently working with one of my former graduate students, Zichun Zhao, on the economic impacts of space weather. Our proxy measure of solar activity is the number of sunspots produced by the sun at a given time and, luckily, this data is <a href="http://www.sidc.be/silso/datafiles">publicly available</a>. </p>
<p>In our empirical analysis, we found that the <a href="https://data.oecd.org/gdp/gross-domestic-product-gdp.htm">Gross Domestic Products (GDP) of the 34-member countries of the Organization for Economic Co-operation and Development</a> decreases as solar activity increases. On average, GDP decreases by at least 0.06 per cent for every increase of one per cent in solar activity. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-space-weather-poses-a-risk-to-the-finance-industry-64621">How space weather poses a risk to the finance industry</a>
</strong>
</em>
</p>
<hr>
<p>We find that the negative economic effects of geomagnetic storms are more significant in northern latitudes. However, the effects of geomagnetic storms <a href="https://www.nasa.gov/topics/earth/features/sun_darkness.html">are not restricted to high latitudes</a> and have been documented in the <a href="http://nora.nerc.ac.uk/id/eprint/500436/">United Kingdom</a>, <a href="https://yle.fi/uutiset/osasto/news/solar_storm-triggered_northern_lights_likely_across_finland__if_clouds_clear/9822507">Finland</a>, <a href="https://phys.org/news/2015-11-sweden-solar-flare-flight.html">Sweden</a>, <a href="https://www.mapfre.com/fundacion/html/revistas/seguridad/n133/en/article2.html">Spain</a>, the <a href="https://www.nap.edu/catalog/12507/severe-space-weather-events-understanding-societal-and-economic-impacts-a">U.S., Canada</a>, <a href="https://www.fin24.com/Tech/News/massive-solar-storm-could-affect-dstv-and-internet-20170908">South Africa</a>, <a href="https://doi.org/10.1051/swsc/2019013">Japan</a>, <a href="http://dx.doi.org/10.1002/cjg2.1261">China</a> and <a href="https://ui.adsabs.harvard.edu/abs/2008cosp%2E%2E%2E37.1491K/abstract">Brazil</a>.</p>
<p>Our empirical results indicate that damages caused by geomagnetic storms are much greater in the information and communications sectors.</p><img src="https://counter.theconversation.com/content/118453/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Batu 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 sun’s phenomena, like flares, can cause solar particles to enter the Earth’s atmosphere, with material effects.Michael Batu, Assistant Professor, Department of Economics, University of WindsorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1193492019-07-02T11:27:03Z2019-07-02T11:27:03ZTotal solar eclipses reveal the dark and stormy side of the sun we never see<figure><img src="https://images.theconversation.com/files/282091/original/file-20190701-105187-ref4z6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4096%2C4083&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The low solar corona as viewed in extreme ultraviolet light. Bright regions are where the most energetic solar storms are born. An eruption in action can be seen in the bottom-left.</span> <span class="attribution"><span class="source">NASA’s Solar Dynamic Observatory (SDO) satellite.</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In astronomy, we have a common saying: “good luck, and clear skies”. For an eclipse chaser like me, this is especially important. We have two minutes and no second chance – one small cloud can spoil everything.</p>
<p>Thousands of tourists turn up to see them, along with a few dozen scientists, for which the eclipse is a unique opportunity to observe the extended atmosphere of the sun – known as the solar corona. Just like Earth, the sun has an atmosphere and magnetic field which extends out to large distances into space. The solar corona is an intense plasma of separated protons and electrons that’s a million degrees Celsius or hotter.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282186/original/file-20190702-28330-h88hkq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sunspots on September 1, 1859, as sketched by Richard Carrington. A and B mark the initial positions of an intensely bright event, which moved over the course of five minutes to C and D before disappearing.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Solar_storm_of_1859#/media/File:Carrington_Richard_sunspots_1859.jpg">Richard Carrington/Wikipedia</a></span>
</figcaption>
</figure>
<p>In this alien environment of hot, magnetised plasma, physics behaves in ways that are poorly understood. Our safety on Earth may depend on understanding it better though – explosive events in the corona can have dramatic and potentially hazardous effects on Earth. </p>
<p>There’s a constant flow of material from this layer of the sun into interplanetary space that’s called the solar wind. In 1859, scientists first discovered it when a solar flare was followed by intense aurora on Earth – also known as Northern or Southern Lights. They were apparently bright enough for people to read newspapers by their light at night. This was known as “the Carrington Event” – electrical currents generated by the flare caused damage to telegraph systems.</p>
<p>As society has become increasingly dependent on technology, understanding space weather and being able to predict it is more important than ever. Eruptions from the sun can damage and disrupt spacecraft, power systems, airlines, communications and GPS systems. A major eruption under the right conditions, like the event in 1859, could cause <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/risa.12765">huge damage to the global economy</a>, on the order of hundreds of billions of dollars.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282188/original/file-20190702-28290-yn5e6j.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">Aurora Borealis over Tromso, Norway. The sun’s solar wind collides with Earth’s atmosphere, creating the lights known as the Northern or Southern Lights.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aurora-borealis-tromso-norway-front-norwegian-497083891?src=A7ZRigJQBbdktHaQ8pt2Ng-1-10&studio=1">Mu Yee Ting/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The dark side of the sun</h2>
<p>Outside of an eclipse, the solar corona is made invisible by the extremely bright light coming directly from the sun’s visible surface – the photosphere. The photosphere is over a million times brighter than even the brightest regions of the corona, so observing the corona is a bit like studying the behaviour of a glowworm hovering next to a lighthouse. Scientists will have spent years, and plenty of funding, preparing for this two-minute phenomenon.</p>
<p>A total eclipse occurs when the moon passes in front of the sun, blocking the sun’s bright disk and casting a deep shadow onto Earth. Over the course of a few hours, the shadow zooms across Earth’s surface faster than Concorde. The “path of totality” – the name for the course the shadow follows – is so large it spans oceans and continents.</p>
<p>Luckily for us, the corona is revealed in all its glory during a total solar eclipse. And luck really is the right word in this context. Imagine the odds of an inhabited planet with intelligent life having a moon that is of the right size and distance to appear the same size in the sky so that it can eclipse the sun. As the moon covers the bright disk of the sun, the surrounding atmosphere appears as a faint ring, with extended rays that point outwards from the sun like a crown – hence the name corona.</p>
<p>To observe the sun safely and study the corona during an eclipse, you need the special filters in a spectrometer. The spectrometer accepts light from the solar corona along a long, narrow entrance slit and during the eclipse, this slit scans to observe the whole corona. The light is split into three channels according to wavelength, and then dispersed onto detectors which record how dense and hot the plasma is – information scientists can’t obtain otherwise.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282203/original/file-20190702-126355-9o5qa6.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">
<figcaption>
<span class="caption">Some of the scientific instruments built and prepared by an international team of scientists led by Prof Shadia Habbal (University of Hawaii) to observe eclipses. The team’s chief engineer, Judd Johnson, is busy fine-tuning one of the telescopes.</span>
<span class="attribution"><span class="source">Shadia Habbal</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://sulis.space">The spectrometer could eventually reside in space</a>, observing the solar corona continuously as part of a mission to watch the sun from a satellite. Scientists could reconstruct the corona’s magnetic field, plasma and other features to finally make sense of this extreme and mysterious environment – and help prepare Earth for its mood swings.</p>
<p>Eclipses such as 2019’s event in South America give a highly-detailed snapshot of the solar atmosphere, and offer a precious opportunity to learn about the hidden layer of the sun which can greatly affect life on Earth. It’s also relatively cheap compared to space missions, and can help scientists develop new tools for looking into space. As always, we hope for good luck, and clear skies.</p><img src="https://counter.theconversation.com/content/119349/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Huw Morgan receives funding from the Science and Technology Facilities Council (UKRI). Aberystwyth's researchers are part of an international team of eclipse chasers led by Professor Shadia Habbal from the University of Hawaii. The high-resolution spectrometer researchers at Aberystwyth use was developed by Professor Adalbert Ding from the Technische Universitaet Berlin.</span></em></p>Scientists spend years preparing for the two-minute window of a total solar eclipse.Huw Morgan, Reader in Physical Sciences, Aberystwyth UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1124152019-06-20T00:16:13Z2019-06-20T00:16:13ZCurious Kids: how is the Sun burning?<figure><img src="https://images.theconversation.com/files/263076/original/file-20190311-86696-1503s74.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C3988%2C2000&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A nuclear reaction is under way inside the Sun. </span> <span class="attribution"><span class="source">Emily Nunell/The Conversation CC-NY-BD</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>If nothing can burn without oxygen then how is the Sun burning? – question from Shashikant Patil.</strong></p>
</blockquote>
<hr>
<p>It’s true that here on Earth, if you want to burn something you need oxygen. But the Sun is different. It is not burning with the same kind of flame you would have on Earth if you burned a candle. </p>
<p>Have you heard of a nuclear reaction? It is a very powerful process that causes a <em>lot</em> of energy to be released. Well, inside the giant ball of gas that we call the Sun, a nuclear reaction is happening right now.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278225/original/file-20190606-40719-bfti09.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">NASA’s Solar Dynamics Observatory captured this image of a solar flare – as seen in the bright flash on the right side – on Sept. 10, 2017.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/feature/goddard/2017/active-region-on-sun-continues-to-emit-solar-flares">Credits: NASA/SDO/Goddard</a></span>
</figcaption>
</figure>
<p>This means light particles are smashing into each other very, very fast. They hit each other so fast and so hard they sort of glue together. This is what scientists call “fusion” and it can cause other elements and atoms to be created. All this activity causes a lot of energy to be released, which heats up everything near it.</p>
<p>The hottest part of the Sun is its core. The heat and light spreads out from the centre of the ball of gas toward the edges, and that’s what makes the Sun glow.</p>
<p>So there is no normal “flame” in the Sun – at least not like the flames we have in a fire here on Earth – because the energy and light and heat is coming from the nuclear reaction. </p>
<p>And because there’s no normal flame, you don’t need oxygen.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-does-the-world-store-nuclear-waste-and-not-just-shoot-it-into-the-sun-or-deep-space-108675">Curious Kids: why does the world store nuclear waste and not just shoot it into the Sun or deep space?</a>
</strong>
</em>
</p>
<hr>
<h2>Did you know the Sun is also loud?</h2>
<p>All this activity inside the Sun creates a lot of sound waves. So the Sun is loud and vibrates like a church bell. </p>
<p>The high temperatures inside make sound waves travel super fast and smash into each other, and that’s what causes the vibration. Solar quakes shake the Sun very ferociously. These can cause what we call “solar flares”, where a powerful burst of energy shoots out from the Sun.</p>
<p>Here’s a video of a solar flare that happened in 2017:</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ybfAvEVpBMo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA.</span></figcaption>
</figure>
<p>I am an astrophysicist fascinated by the vibrations of the Sun. I am searching to discover more quakes inside the Sun and other stars, too (after all, the Sun is just a star). </p>
<p>If you are interested in finding solar quakes, too, check out the pictures from NASA’s <a href="https://sdo.gsfc.nasa.gov/">Solar Dynamics Observatory</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-is-there-anything-hotter-than-the-sun-105748">Curious Kids: Is there anything hotter than the Sun?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/112415/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alina Donea 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>It’s true that here on Earth, if you want to burn something you need oxygen. But the Sun is different. It is not burning with the same kind of flame you would have on Earth if you burned a candle.Alina Donea, Senior Lecturer, Monash Centre for Astrophysics, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1059832018-11-08T03:24:21Z2018-11-08T03:24:21ZBlasts from the past: how massive solar eruptions ‘probably’ detonated dozens of US sea mines<figure><img src="https://images.theconversation.com/files/243813/original/file-20181104-83635-1obzabs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar flares captured on the Sun.</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/content/goddard/sunspot-ar2192-release-x2.0-class-solar-flare-on-oct-26-2014">NASA/SDO</a></span></figcaption></figure><p>An extraordinary account of the impact space weather had on military operations in Vietnam in 1972 was found buried in the US Navy archives, according to a newly published article in <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018SW002024">Space Weather</a>.</p>
<p>On August 4, 1972, the crew of a US Task Force 77 aircraft flying near a naval minefield in the waters off Hon La observed 20 to 25 explosions over about 30 seconds. They also witnessed an additional 25 to 30 mud spots in the waters nearby. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/its-never-been-more-important-to-keep-an-eye-on-space-weather-65648">It's never been more important to keep an eye on space weather</a>
</strong>
</em>
</p>
<hr>
<p><a href="http://www.navweaps.com/Weapons/WAMUS_Mines.php#Vietnam_War_%22Destructor%22_Mines">Destructor sea mines</a> had been deployed here during Operation Pocket Money, a mining campaign launched in 1972 against principal North Vietnamese ports.</p>
<p>There was no obvious reason why the mines should have detonated. But it has now emerged the US Navy soon turned its attention to extreme solar activity at the time as a probable cause.</p>
<p>The more we can understand the impact of such space weather on technology then the better we can be prepared for any future extreme solar activity.</p>
<h2>A solar theory</h2>
<p>As detailed in a now declassified <a href="https://vva.vietnam.ttu.edu/repositories/2/digital_objects/83295">US Navy report</a>, the event sparked an immediate investigation about the potential cause(s) of the random detonations of so many sea mines. </p>
<p>The sea mines deployed had a self-destruct feature. But the minimum self-destruct time on these mines was not for another 30 days, so something else was to blame.</p>
<p>On August 15, 1972, the Commander in Chief of the US Pacific Fleet, Admiral Bernard Clarey, asked about a hypothesis that <a href="https://theconversation.com/massive-sunspots-and-huge-solar-flares-mean-unexpected-space-weather-for-earth-83677">solar activity</a> could have caused the mine detonations. </p>
<p>Many of the mines deployed were <a href="http://www.navweaps.com/index_tech/tech-068.php#Magnetic_Mines">magnetic influence sea mines</a> that were designed to detonate when they detected changes in the magnetic field. </p>
<p>Solar activity was then well known to cause <a href="https://theconversation.com/damaging-electric-currents-in-space-affect-earths-equatorial-region-not-just-the-poles-45073">magnetic field changes</a>, but it wasn’t clear whether or not the Sun could cause these unintentional detonations. </p>
<h2>Solar flares</h2>
<p>Early August in 1972 saw some of the most intense <a href="https://link.springer.com/article/10.1007%2FBF00152736">solar activity</a> ever recorded. </p>
<p>A sunspot region, denoted MR 11976, set off a series of intense <a href="https://www.space.com/11506-space-weather-sunspots-solar-flares-coronal-mass-ejections.html">solar flares</a> (energetic explosions of electromagnetic radiation), coronal mass ejections (eruptions of solar plasma material that typically accompany flares) and clouds of charged particles travelling close to the speed of light. </p>
<p>Those conducting the investigation into the mine incident visited the Space Environment Laboratory at the National Oceanographic and Atmospheric Administration (<a href="https://www.swpc.noaa.gov/">NOAA</a>) near Boulder, Colorado, to speak to space scientists.</p>
<p>One of the scientists at NOAA at the time was the now Emeritus Professor Brian Fraser, from Australia’s <a href="https://www.newcastle.edu.au/research-and-innovation/centre/csp/about-us">Newcastle University</a>, and it’s an event he told me he remembers well: </p>
<blockquote>
<p>I was on my first sabbatical leave at NOAA working with Wallace (Wally) Campbell’s group, and one day in Wally’s office I noticed a group of US Navy brass hat gentlemen and a couple of dark suits.</p>
</blockquote>
<p>Brian said he had later quizzed Wally on what was going on, and Wally explained they were concerned about geomagnetic field changes triggering sea mines laid in Hai Phong, North Vietnam.</p>
<blockquote>
<p>There was no mention whether or not they had exploded but maybe Wally was being coy. And of course it was all probably top secret then.</p>
</blockquote>
<p>The outcome of this investigation, as stated in the declassified US Navy <a href="https://vva.vietnam.ttu.edu/repositories/2/digital_objects/83295">report</a>, detailed “a high degree of probability” that the Destructor mines had been detonated by the August solar storm activity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=151&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=151&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=151&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=189&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=189&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243814/original/file-20181104-83629-171fwbu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=189&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Declassified: excerpt from U.S. Navy Report, Mine Warfare Project Office - The Mining of North Vietnam, 8 May 1972 to 14 January 1973.</span>
<span class="attribution"><a class="source" href="https://vva.vietnam.ttu.edu/repositories/2/digital_objects/83295">1070416001, Glenn Helm Collection, The Vietnam Center and Archive, Texas Tech University</a></span>
</figcaption>
</figure>
<h2>Solar interference</h2>
<p>Solar storms <a href="https://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html#q13">cause</a> strong magnetic field fluctuations, which impact large power grid infrastructure, particularly in the high-latitude regions beneath the northern and southern auroras. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/GrnGi-q6iWc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Solar flares captured by NASA and ESA.</span></figcaption>
</figure>
<p>The storms of early August 1972 were no different. There were numerous reports across North America of <a href="https://ieeexplore.ieee.org/document/4075456">power disruptions</a> and <a href="https://ieeexplore.ieee.org/document/6773728">telegraph line outages</a>. Now that light has been shone on the impact of these events on sea mine operations in 1972, the scientific community has another clear example of space weather impacts on technologies.</p>
<p>The intensity of the early August activity peaked when an <a href="https://www.nasa.gov/mission_pages/sunearth/news/X-class-flares.html">X-class</a> solar flare at 0621 UT August 4, 1972, launched an ultra-fast coronal mass ejection that reached Earth in the record time of 14.6 hours. The solar wind normally takes two to three days to reach Earth. </p>
<p>Scientists think that the previous slower ejections from earlier flares had cleared the path for this fast disturbance, similar to what was observed by the <a href="https://stereo.gsfc.nasa.gov/">STEREO</a> spacecraft in <a href="https://theconversation.com/solar-eruption-could-help-earth-prepare-for-technology-melt-down-18747">July 2012</a>.</p>
<p>It’s the impact of this fast disturbance in the solar wind on the Earth’s magnetosphere that <a href="https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2018SW002024">probably caused</a> the detonation of the Destructor mines.</p>
<h2>Using the past to predict the future</h2>
<p>The <a href="http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html">Dst index</a>, measured in nano-Tesla (nT), is a typical measure of the disturbance level in the Earth’s magnetic field – the more negative, the more intense the storm. </p>
<p>Some recent extreme solar storms, according to this scale, include the 2015 St Patrick’s Day storm (<a href="http://wdc.kugi.kyoto-u.ac.jp/dst_provisional/201503/index.html">-222 nT</a>) and the 2003 Halloween storm (<a href="http://wdc.kugi.kyoto-u.ac.jp/dst_final/200310/index.html">-383 nT</a>).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-the-weather-is-like-on-a-star-can-help-in-the-search-for-life-56275">What the 'weather' is like on a star can help in the search for life</a>
</strong>
</em>
</p>
<hr>
<p>Interestingly, the extreme activity in August 1972 was far less intense on this scale, only weighing in at <a href="http://wdc.kugi.kyoto-u.ac.jp/dst_final/197208/index.html">-125 nT</a>. </p>
<p>Exactly why this storm reached extreme level on some measures, such as its high speed from the Sun, but not on the typical Dst scale is a topic of significant discussion within the scientific <a href="https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/91GL02783">literature</a>.</p>
<p>Given the complexities of this event, <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018SW002024">this new paper</a> lays out a grand challenge to the space weather community to use our modern modelling techniques to reexamine this solar event. Hopefully, understanding these strange events will better prepare us for future solar eruptions.</p><img src="https://counter.theconversation.com/content/105983/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Carter receives funding from the Australian Research Council and the Australian Antarctic Science Program. </span></em></p>When dozens of US mines planted in waters off the Vietnam coast detonated almost simultaneously in 1972, all eyes turned to the Sun for an explanation.Brett Carter, Senior lecturer, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/836772017-09-08T00:18:31Z2017-09-08T00:18:31ZMassive sunspots and huge solar flares mean unexpected space weather for Earth<figure><img src="https://images.theconversation.com/files/185178/original/file-20170907-9585-c1fei2.jpg?ixlib=rb-1.1.0&rect=183%2C0%2C1615%2C1074&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A huge solar flare flashes in the middle of the sun on Sept. 6, 2017. A separate image of the Earth provides scale.</span> <span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/12706">NASA/GSFC/SDO</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>If you still have your solar viewing glasses from the eclipse, now is a good time to slap them on and look up at the sun. You’ll see two big dark areas visible on our star. These massive sunspots are regions of intense and complicated magnetic fields that can produce solar flares – bursts of high-energy radiation. You can just make them out with solar viewing glasses, but they’re better viewed through a solar telescope. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"905107565406818304"}"></div></p>
<p>These two huge sunspots are currently causing quite a bit of consternation and interest. The solar storms they’ve sent toward Earth may affect communications and other technologies like GPS and radio signals. They’re causing amazing displays of the Northern and Southern Lights. And space weather scientists like us are excited because we wouldn’t normally expect this much activity from the sun at the moment.</p>
<p>The sun goes through 11-year cycles of solar activity. What scientists call a solar maximum is the time in the cycle when the sun is putting out the most energy. That’s when we tend to see the most sunspots, solar flares and associated solar storms. Some solar maxima are larger or more active than others – such as the 1990-1991 solar max. But this last cycle, which peaked in 2014, was <a href="https://solarscience.msfc.nasa.gov/predict.shtml">quite small</a>, and there were few large geomagnetic storms.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185117/original/file-20170907-9538-1uarzku.jpeg?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">The number of sunspots varies over the years, but you’d expect to see more during solar maxima and fewer during solar minima.</span>
<span class="attribution"><a class="source" href="http://www.swpc.noaa.gov/products/goes-x-ray-flux">NOAA</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We’re heading into the bottom of solar minimum, when the sun tends to have fewer sunspots, <a href="https://www.nasa.gov/content/goddard/the-difference-between-flares-and-cmes">solar flares</a> and <a href="http://www.swpc.noaa.gov/phenomena/coronal-mass-ejections">coronal mass ejections</a> – large <a href="http://earthsky.org/space/what-are-coronal-mass-ejections">expulsions of plasma, electrons and ions, and magnetic fields</a>. But despite where we are in the sun’s cycle, activity on the sun has dramatically picked up over the past few days. On and off, these two sunspots have been flaring and shooting out coronal mass ejections, directed toward Earth.</p>
<p>So what’s going on with the sun? And should we be concerned about this somewhat out-of-character solar behavior?</p>
<h2>Here’s what’s happened so far</h2>
<p>On September 4, the sun started sputtering. A moderately large flare (<a href="https://www.nasa.gov/mission_pages/sunearth/news/classify-flares.html">classified as an M5.5</a>) erupted at approximately 18:30 UTC. It produced a coronal mass ejection aimed at Earth.</p>
<p>The sun continued to flare on September 5. A <a href="https://helios.gsfc.nasa.gov/sep.html">solar energetic particle</a> event from the previous day’s activity arrived at the Earth, where it likely affected radio communications as well as the health of satellite systems.</p>
<p>On September 6, the sun produced two massive <a href="https://www.nasa.gov/mission_pages/sunearth/news/X-class-flares.html">X-class flares</a>. This is the category for the strongest of all solar flares.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"905456884911661057"}"></div></p>
<p>NASA announced one was <a href="https://www.nasa.gov/feature/goddard/2017/active-region-on-sun-continues-to-emits-solar-flares">the most powerful since at least 2008</a>. It <a href="https://twitter.com/NASASun/status/905822026488619008">produced another coronal mass ejection</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185122/original/file-20170907-9542-wyifki.jpeg?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">The second and strongest of the two X-class flares on September 6 produced a coronal mass ejection directed at Earth.</span>
<span class="attribution"><span class="source">NOAA</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Over the next day, the same sunspots continued to spit out more solar flares. It took about an hour for the <a href="https://helios.gsfc.nasa.gov/sep.html">solar energetic particles</a> they emitted to arrive at Earth. These protons are incredibly fast-moving. They can affect communication systems, typically in the polar regions where they are more likely to enter into the Earth’s atmosphere. As with all increases of radiation in space, they can also affect satellite systems and the health of astronauts. </p>
<p>Early in the morning hours of September 7 in the U.S., that first coronal mass ejection that erupted from the sun three days earlier arrived at Earth. Because of the way its magnetic field aligned with Earth’s, it <a href="http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201709/index.html">generated only a small geomagnetic storm</a>.</p>
<p>After being detected by spacecraft upstream from Earth in the solar wind, the massive coronal mass ejection from September 6 also hit Earth on the evening of September 7 EDT. Its arrival was a few hours earlier than <a href="http://www.swpc.noaa.gov/products/wsa-enlil-solar-wind-prediction">space weather forecasting agencies</a> around the world predicted.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185185/original/file-20170907-9603-8u5a2w.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">Both sunspots are visible on the sun’s surface, as well as the flare in the solar atmosphere.</span>
<span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/12706">NASA/GSFC/SDO</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>What other effects will Earth see?</h2>
<p>All this solar activity has already caused a couple of radiation storms in Earth’s high latitude regions that <a href="http://www.swpc.noaa.gov/phenomena/solar-flares-radio-blackouts">blacked out radio communication</a> at certain frequencies. The impacts extended toward the equator and have affected high-frequency communications, including ham radios, which are used in emergency and disaster relief management. Radio fade-out maps from the <a href="http://www.sws.bom.gov.au/HF_Systems/6/2/2">Australian Bureau of Meteorology</a> show that <a href="http://www.swpc.noaa.gov/communities/radio-communications">high-frequency radio communication disruptions</a> have likely occurred in the same areas being pummeled by Hurricane Irma.</p>
<p>There has likely been a <a href="https://www.engadget.com/2017/09/07/a-huge-solar-flare-temporarily-knocked-out-gps-communications/">loss of global navigation system satellite communications</a> in those same areas, but it will take time for the data to be analyzed and for us to gain a full understanding of how this space weather activity has affected those on the ground. The <a href="https://theconversation.com/are-you-a-frequent-flyer-solar-storm-radiation-can-be-harmful-28775">radiation storms</a> may also force flights over the polar regions to reroute to avoid increased radiation exposures for people on board and potential loss of communication and navigation systems for aircraft on these paths. </p>
<p>With the collision of the coronal mass ejection from this X-class flare with Earth come other impacts for the near-Earth space environment. <a href="https://theconversation.com/divert-power-to-shields-the-solar-maximum-is-coming-11228">Geomagnetic storms</a>, like the one currently in progress, are known to wreak havoc on a range of satellite and ground-based communication technologies, as well as <a href="https://theconversation.com/damaging-electric-currents-in-space-affect-earths-equatorial-region-not-just-the-poles-45073">power grids</a>, GPS/GNSS, and orbit predictions of satellites and space debris. It is also very likely to produce dazzling aurora activity as far south as the northern U.S. and Europe in the Northern Hemisphere, and as far north as southern Australia and New Zealand in the Southern Hemisphere. </p>
<p>While scientists and aurora-hunting enthusiasts closely watch the storm’s ongoing effects, others will be bracing for problems and disruptions to the many technological services that will be affected.</p>
<p>We don’t need to worry about this coronal mass ejection being “the big one” – a solar storm direct hit that could cause widespread power blackouts and trigger <a href="https://science.nasa.gov/science-news/science-at-nasa/2014/23jul_superstorm/">as much as US$2 trillion worth of damage</a>, according to a National Academy of Sciences study. But this storm, on the back of this month’s abnormally active space weather, may wind up on the larger end of the scale, and will be the subject of lots of analysis and research.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185120/original/file-20170907-9568-1nt2u26.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">Images of the sun during solar cycle 23. You typically see more activity during a solar maximum (2001) than during a minimum (1996 or 2006).</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/mission_pages/sunearth/science/solarcycle23.html">ESA&NASA/SoHO</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We don’t yet fully understand everything that is happening. But the activity over the past few days, when the sun should be within its quietest period, shows that significant space weather events are possible at any stage of the 11-year solar cycle.</p>
<p>You can help us study this and other solar storms as a citizen scientist. Sign up for <a href="http://www.aurorasaurus.org/">Aurorasaurus</a> and let us know if you observe aurorae with this event.</p><img src="https://counter.theconversation.com/content/83677/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexa Halford receives funding from NASA. </span></em></p><p class="fine-print"><em><span>Brett Carter receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Julie Currie receives funding from the Australian Research Council. </span></em></p>At a time in the sun’s cycle when space weather experts expect less solar activity, our star is going bonkers with solar flares and coronal mass ejections. What effects will Earth feel?Alexa Halford, Researcher in Physics and Astronomy, Dartmouth CollegeBrett Carter, Senior Research Fellow, RMIT UniversityJulie Currie, Research Officer, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/711782017-01-19T11:13:57Z2017-01-19T11:13:57ZSix cosmic catastrophes that could wipe out life on Earth<figure><img src="https://images.theconversation.com/files/153030/original/image-20170117-23036-q3go68.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A gamma ray burst close to Earth could be devastating.</span> <span class="attribution"><span class="source">ESO/A. Roquette</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>If you ask yourself what the biggest threat to human existence is you’d probably think of nuclear war, global warming or a large-scale pandemic disease. But assuming we can overcome such challenges, are we really safe?</p>
<p>Living on our blue little planet seems safe until you are aware of what lurks in space. The following cosmic disasters are just a few ways humanity could be severely endangered or even wiped out. Happy reading!</p>
<h2>1. High energy solar flare</h2>
<p>Our sun is not as peaceful a star as one might initially think. It creates strong magnetic fields that generate impressive sun spots, sometimes many times larger than Earth. It also ejects a stream of particles and radiation – the solar wind. If kept in check by Earth’s magnetic field, this wind can cause beautiful northern and southern lights. But when it becomes stronger, it can also influence radio communication or cause power outages.</p>
<p>The most powerful magnetic solar storm documented hit Earth in 1859. The incident, called the <a href="http://www.swsc-journal.org/articles/swsc/pdf/2013/01/swsc130015.pdf">Carrington Event</a>, caused huge interference with rather small scale electronic equipment. Such events must have happened several times in the past, too, with humans surviving. </p>
<p>But only in recent years have we become entirely dependent on electronic equipment. The truth is we would <a href="http://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdf">suffer greatly</a> if we underestimate the dangers of a possible Carrington or even more powerful event. Even though this would not wipe out humanity instantly, it would represent an <a href="http://gizmodo.com/what-would-happen-if-a-massive-solar-storm-hit-the-eart-1724650105">immense challenge</a>. There would be no electricity, heating, air conditioning, GPS or internet – food and medicines would go bad.</p>
<h2>2. Asteroid impact</h2>
<p>We are now well <a href="https://asteroidday.org/">aware of the dangers asteroids could pose to humanity</a> – they are, after all, thought to have contributed to the extinction of the dinosaurs. Recent research has made us aware of the <a href="https://theconversation.com/now-thats-a-close-shave-secrets-of-the-halloween-asteroid-headed-for-earth-49820">large host of space rocks</a> in our solar system that could pose danger. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=454&fit=crop&dpr=1 600w, https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=454&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=454&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=571&fit=crop&dpr=1 754w, https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=571&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/153061/original/image-20170117-23050-10v9qpq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=571&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dangerous impact.</span>
<span class="attribution"><span class="source">Don Davis/NASA</span></span>
</figcaption>
</figure>
<p>We are at the starting point of <a href="https://www.nasa.gov/planetarydefense/aida">envisaging and developing systems</a> for protecting us against some of the smaller asteroids that could strike us. But against the bigger and rarer ones we are quite helpless. While they would not always destroy Earth or even make it uninhabitable, they could wipe out humanity by causing enormous tsunamis, fires and other natural disasters.</p>
<h2>3. Expanding sun</h2>
<p>Where the previous cosmic dangers occur at the roll of a dice with a given probability, we know for certain that our sun will <a href="http://sro.sussex.ac.uk/1800/2/DoomsdayResub.pdf">end its life in 7.72 billion years</a>. At this point, it will throw off its outer atmosphere to form a planetary nebula, ending up as a stellar remnant know as a “white dwarf”. </p>
<p>But humanity will not experience these final stages. As the sun becomes older, it will become cooler and larger. By the time it becomes a <a href="https://theconversation.com/what-is-the-biggest-star-in-the-universe-52026">stellar giant</a> it will be big enough to engulf both Mercury and Venus. Earth might seem safe at this point, but the sun will also create an extremely strong solar wind that will slow down the Earth. As a result, in about 7.59 billion years, our planet will spiral into the outer layers of the hugely expanded dying star and <a href="http://sro.sussex.ac.uk/1800/2/DoomsdayResub.pdf">melt away forever</a>.</p>
<h2>4. Local gamma ray burst</h2>
<p>Extremely powerful outbursts of energy called <a href="http://www.bbc.co.uk/science/space/universe/sights/gamma_ray_bursts">gamma ray bursts</a> can be caused by binary star systems (two stars orbiting a common centre) and supernovas (exploding stars). These energy bursts are extremely powerful because they focus their energy into a narrow beam lasting no longer than seconds or minutes. The resulting radiation from one could damage and destroy our ozone layer, leaving life vulnerable to the sun’s harsh UV radiation. </p>
<p>Astronomers have discovered a star system – <a href="http://www.nature.com/articles/19033.epdf?referrer_access_token=tuD5AI9j4Eq3pLY2hFNl1tRgN0jAjWel9jnR3ZoTv0MRJSy94bsA9uUTZGJqAtFgRMWmmI-vrVpT7GkbP3NdIlLGAW8LnKKSbGobJd4nrg8I1yZlETA9q7-GM_JXc7c7KdYl64POgyOtdVTjJtjUQbmGY-3YQtAN9ZL-Nw9uKJu5wJ6o_1nNZRPh8g-Lrvs0osQ1A5NHgCYQDR8ZbiEkbk55V3SOahqSf_2ZDHqGWBc%3D&tracking_referrer=www.bbc.co.uk">WR 104</a> – that could host such an event. WR 104 is about 5,200-7,500 light years away, which is not far enough to be safe. And we can only guess when the burst will happen. Luckily, there is the possibility that the beam could miss us entirely when it does. </p>
<h2>5. Nearby supernovas</h2>
<p>Supernova explosions, which take place when a star has reached the end of its life, occur on average once or twice every 100 years in our Milky Way. They are more likely to occur closer to the dense centre of the Milky Way and we are about two-thirds of the way from the middle – not too bad.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/153065/original/image-20170117-23043-ty0qza.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">
<figcaption>
<span class="caption">SN 1994D (bright spot on the lower left), a type Ia supernova in the NGC 4526 galaxy.</span>
<span class="attribution"><span class="source">NASA/ESA</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>So can we expect a nearby supernova anytime soon? The star Betelgeuse – a <a href="http://study.com/academy/lesson/red-supergiant-definition-facts-life-cycle.html">red super giant</a> <a href="http://www.space.com/22009-betelgeuse.html">nearing the end of its life</a> – in the constellation of Orion is just 460-650 light years away. It could become a supernova now or in the next million years. Luckily, astronomers have estimated that a supernova would need to be <a href="https://www.nasa.gov/topics/earth/features/2012-supernova.html">within at least 50 light years of us</a> for its radiation to damage our ozone layer. So it seems this particular star shouldn’t be too much of a concern.</p>
<h2>6. Moving stars</h2>
<p>Meanwhile, a <a href="http://iopscience.iop.org/article/10.1088/2041-8205/800/1/L17/meta">wandering star on its path through the Milky Way</a> might come so close to our sun that it would interact with the rocky “Oort cloud” at the edge of the solar system, which is the source of our comets. This might lead to an increased chance of a huge comet hurtling to Earth. Another roll of the dice.</p>
<p>The sun itself follows a <a href="https://www.newscientist.com/article/mg21228411-500-earths-wild-ride-our-voyage-through-the-milky-way/">path through the Milky Way</a> that takes us through more or less dense patches of interstellar gas. Currently we are within a <a href="https://arxiv.org/pdf/astro-ph/0401428v1.pdf">less dense bubble</a> created by a supernova. The sun’s wind and solar magnetic field help create a bubble-like region surrounding our solar system – <a href="https://en.wikipedia.org/wiki/Heliosphere">the heliosphere</a> – which shields us from interacting with the interstellar <a href="http://www.space.com/22729-voyager-1-spacecraft-interstellar-space.html">medium</a>. When we leave this region in 20,000 to 50,000 years (depending on current observations and models), our heliosphere could be less effective, exposing Earth. We would possibly <a href="https://www.newscientist.com/article/mg18524874-300-interstellar-gas-cloud-linked-to-snowball-earth/">encounter increased climate change</a> making life more challenging for humanity – if not impossible.</p>
<h2>And life goes on…</h2>
<p>The end of humanity on Earth is a given. But this is not something to make us crawl under a table. It is something that we cannot change, similar to our lives having a definite start and end. This is what defines us and makes us realise that the only thing we can do is make the most of our time on Earth. Especially when we know that Earth needs a careful balance to sustain humanity. </p>
<p>All the above scenarios harbour possible destruction, but in every instance they also offer beauty and wonder. In many cases, they produce what allowed us to be created. So rather than looking into the night sky and wondering what will kill us next, we should marvel at the depth of space, the wonders therein and the sublime nature of the universe. Be inspired by space. It offers future and meaning.</p><img src="https://counter.theconversation.com/content/71178/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Brown 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>If we survive for another 7.59 billion years, our planet will spiral into the outer layers of the dying sun and melt away forever.Daniel Brown, Lecturer in Astronomy, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/656482016-10-02T19:12:40Z2016-10-02T19:12:40ZIt’s never been more important to keep an eye on space weather<figure><img src="https://images.theconversation.com/files/139141/original/image-20160926-2440-1eybr8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coronal mass ejections can play havoc with Earthbound communications.</span> <span class="attribution"><a class="source" href="http://www.nasa.gov/multimedia/imagegallery/image_feature_759.html">NASA/JPL</a></span></figcaption></figure><p>As technology becomes increasingly vital in our day-to-day lives, we are more susceptible to “<a href="http://www.spaceweather.org/ISES/swxeff/swh.html">space weather</a>”. What begins with dark spots on the Sun’s surface, and magnetic field disruptions in the Sun’s atmosphere, can result in widespread technological disturbance. With our increasing reliance on telecommunications and other technologies, monitoring what happens in space has never been more important.</p>
<p>During a solar flare, pulses of electromagnetic radiation are emitted into space, showering the solar system with intense radio waves, X-rays and ultraviolet radiation. At times, these flares are accompanied by solar material, in what is called a “coronal mass ejection”, or CME. These disturbances contribute to the variability in the near-Earth space environment. </p>
<p>A lot of the technology on which we depend is susceptible to these disturbances. Satellites use radio waves to communicate, and thus are <a href="https://theconversation.com/predicting-daily-space-weather-will-help-keep-your-gps-on-target-34750">vulnerable to radio signal disruption</a>, but so are more Earth-bound technologies – CMEs have been linked to the <a href="http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=4538419">failure of some power grids</a> and could impact <a href="http://onlinelibrary.wiley.com/doi/10.1002/2016SW001411/full">high-speed railways</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sg3NAdOYp8Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA captured images of a massive cloud of solar material in 2012.</span></figcaption>
</figure>
<h2>Disturbing history</h2>
<p>The first documented link between a CME and technology comes from 1841, when a telegraph system was affected by strong magnetic field fluctuations during a magnetic storm. “On the 18th of October, 1841, a very intense magnetic disturbance was recorded,” the <a href="http://onlinelibrary.wiley.com/doi/10.1002/swe.20091/pdf">journal Nature reported</a>. The disturbance caused a train to be delayed by 16 minutes as “it was impossible to ascertain if the line was clear at Starcross”.</p>
<p>The superintendent of Exeter station reported the next morning that “someone was playing tricks with the instruments, and would not let them work”, demonstrating how innocuous such events may appear. This event was less than 20 years before the largest known space weather event, the infamous <a href="https://science.nasa.gov/science-news/science-at-nasa/2008/06may_carringtonflare">Carrington</a> geomagnetic storm in 1859, during which northern auroras were seen as far south as El Salvador in Central America.</p>
<p>The 20th century also had its fair share of severe geomagnetic storms. Radio and telephone communications were widely disrupted during a <a href="http://www.sciencedirect.com/science/article/pii/S1364682600001747?np=y">May 1921 storm</a> that saw the <a href="http://query.nytimes.com/mem/archive-free/pdf?res=9C05E7D81E3FEE3ABC4D52DFB366838A639EDE">aurora borealis outshine Broadway in New York City</a>. A telephone station in Sweden burned out, a New York telegraph operator claimed that “he was driven away from his instrument by a flare of flame which enveloped the switchboard and ignited the building”, and telegraph lines in France “seemed possessed by evil spirits”. The event even touched Australia, with the <a href="http://trove.nla.gov.au/newspaper/article/1757393?browse=ndp%3Abrowse%2Ftitle%2FA%2Ftitle%2F13%2F1921%2F05%2F17%2Fpage%2F413394%2Farticle%2F1757393">Argus</a> reporting disruptions to telephone services between Melbourne, Sydney and Brisbane.</p>
<h2>CMEs and the Second World War</h2>
<p>Seventy-five years ago, on September 18-19, 1941, there was <a href="https://eos.org/features/the-geomagnetic-blitz-of-september-1941?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz091616">another great geomagnetic storm</a>, which also led to <a href="http://pqasb.pqarchiver.com/washingtonpost_historical/doc/151432091.html?FMT=ABS&FMTS=ABS:AI&type=historic&date=Sep+19%2C+1941&author=&pub=The+Washington+Post++%281923-1954%29&edition=&startpage=1&desc=Northern+Light+Show+Visits+South">aurora sightings</a> in the skies across the middle latitudes of the United States. At the time, Europe was at war and the Allies were heavily dependent on the flow of supplies across the North Atlantic Ocean.</p>
<p>The geomagnetic storm appeared to have influenced the North Atlantic battle theatre by causing disruptions to short-wave radio transmissions, as <a href="http://uboat.net/books/item/2388">reported</a> by Kapitänleutnant Eitel-Friedrich Kentrat on board German U-boat U-74, which was actively hunting in the area. The storm had negative consequences for the Allied supply ships on route from North America to England, who found themselves travelling on a night that had been rendered as “bright as day”, according to Kentrat. Throughout the night, a Canadian convoy was attacked by U-74 and HMCS Lévis was torpedoed and sunk. Eighteen people lost their lives and 40 were rescued. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=520&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=520&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=520&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=653&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=653&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138515/original/image-20160920-12481-1n3ufz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=653&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 great solar flare of 23 May 1967 (bright region in top half of solar image). Extreme emissions were recorded in the radio, visible, ultraviolet and X-ray portions of the electromagnetic spectrum.</span>
<span class="attribution"><span class="source">NSO H alpha</span></span>
</figcaption>
</figure>
<h2>A Solar Burst that could have taken us to war</h2>
<p>A great space weather storm in <a href="http://onlinelibrary.wiley.com/doi/10.1002/2016SW001423/abstract">May 1967</a> began with a colossal solar radiation burst. Ultimately it produced a CME-driven, record-setting storm in Earth’s magnetic field (the magnetosphere) and upper atmosphere, including the ionosphere between 80km and 500km altitude. It currently stands as the eighth most intense storm since magnetic records began and one of the <a href="http://onlinelibrary.wiley.com/doi/10.1029/2005RG000193/full">largest ever</a> in the ionosphere.</p>
<p>The intense solar radiation burst was accompanied by several additional flares and other space-based phenomena that negatively impacted radio surveillance and communications across North America. One of these systems was responsible for detecting incoming ballistic missiles over the polar region, providing a 15-minute warning to Canada, the United States and Britain. To the uninformed, the event easily have been misinterpreted as system radio jamming, potentially an act of war or an indication of an impending attack.</p>
<p>This disturbance came during a tense time in the Cold War. The United States and Soviet Union were actively challenging each other for the top position as the dominant global superpower. The Vietnam War was ramping up and tensions were building in the Middle East, leading eventually to the Six-Day War in June 1967.</p>
<h2>Why we need more monitoring</h2>
<p>Crisis was averted during the Cold War largely because of the space monitoring that was already in place. The US Air Force had established solar observatories after the Second World War, which allowed space weather forecasters and the US Department of Defense to understand that the “jamming” was from a natural source.</p>
<p>Nowadays, as we become even more dependent on communications technology, an <a href="https://theconversation.com/solar-eruption-could-help-earth-prepare-for-technology-melt-down-18747">extreme space weather event</a> could have even more severe <a href="https://theconversation.com/divert-power-to-shields-the-solar-maximum-is-coming-11228">consequences</a>. Therefore, as technology advances, so must our knowledge of the near-Earth space environment, a goal that many cooperative space weather researchers and <a href="http://www.spaceweather.org/ISES/intro/intro.html">organisations</a> around the world are continually striving to achieve.</p><img src="https://counter.theconversation.com/content/65648/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Carter receives funding from the Victorian Postdoctoral Research Fellowship Program and the Australian Research Council.</span></em></p><p class="fine-print"><em><span><a href="mailto:delores.knipp@colorado.edu">delores.knipp@colorado.edu</a> receives funding from the US National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA) and the US Air Force Office of Scientific Research (AFOSR) . She is affiliated with American Geophysical Union (AGU) and is Editor in Chief for AGU's Space Weather journal.</span></em></p>There’s a disturbing history of solar flares taking out the technology we depend on. As tech becomes more and more vital, knowing what is happening in space is growing ever more crucial.Brett Carter, RMIT Research Fellow in Space Weather and Ionospheric Physics, RMIT UniversityDelores Knipp, Research professor, University of Colorado BoulderLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/646212016-08-31T15:59:26Z2016-08-31T15:59:26ZHow space weather poses a risk to the finance industry<figure><img src="https://images.theconversation.com/files/136083/original/image-20160831-30762-19fml4f.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.flickr.com/photos/gsfc/8640589344/in/photolist-eaxhbm-ro44H3-pa3e7R-rjQRm5-psPv5W-q1Gxw5-6zxYvb-puPSSC-d5UHiu-nDePcB-5utymV-absVw6-dSDgae-bozyiY-97nyAt-4PnMyH-qaiCAK-awVaEv-pAwBok-8Chf6V-5e21hd-oqfcK2-8oC7N1-dyKu1P-qrKaYe-oUoA7k-dyKuX4-asBADA-qvvYiY-p7Pc2U-egcv1D-dtvHND-pvyZdV-ksysHk-dyKFkM-dtvHbg-7LQndv-ksLoo4-pvLg2g-bBeBbR-nY7r2k-cmkfV-qqyNm8-jCfMcP-KTiyQ-rhRoCb-bzakEj-dtBfWJ-jb2RnM-pLujVY">NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The conventional risks to finance – interest rate changes, currency fluctuations or just the outcome of a non-binding referendum – are well known. But there is another factor that can affect banking and investment funds, which most of us are less aware of: “space weather”.</p>
<p>The consequences of living close to a dynamic star such as the sun – apart from it keeping our planet at just the right temperature to exist – are the eruptions and explosions it produces. These can can cause disturbances to the Earth’s magnetic field and atmosphere which can disrupt a wide range of technological systems that modern society relies on. These include the technology intrinsic to the finance industry. </p>
<p>In the 1800s, it was the telegraph system that was affected. It experienced disruptions to its operation and there were office fires as equipment started sparking during strong space weather storms. Since then, our use of technology has expanded and space weather can cause more damage as a result. Railways, electricity networks and radio communications are all vulnerable to space weather. And the advent of the space age, with our growing dependency on satellites for all forms of communication, has made the problem even more acute.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/136086/original/image-20160831-30780-ov53rk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artist’s illustration of events on the sun changing the conditions in near-Earth space.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gsfc/6819077978/in/photolist-bozyiY-8Chf6V-97nyAt-5e21hd-4PnMyH-oqfcK2-8oC7N1-qaiCAK-awVaEv-dyKu1P-KTiyQ-qrKaYe-oUoA7k-dyKuX4-asBADA-qvvYiY-p7Pc2U-rhRoCb-bzakEj-egcv1D-dtBfWJ-dtvHND-pvyZdV-ksysHk-dyKFkM-dtvHbg-7LQndv-ksLoo4-pvLg2g-bBeBbR-nY7r2k-cmkfV-qqyNm8-jCfMcP-8rjYy5-jb2RnM-pLujVY-omgtsY-mCvZ48-araToX-cE76Ss-egifLq-bESXH-2YNBVy-dyR2S9-pgV6G2-pQZrk7-9iDfMp-oX69UY-8V9XY">NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>A wake-up call to the problem came when the Earth experienced a geomagnetic storm that caused Canada’s Hydro-Québec electricity grid to experience strong voltage fluctuations. This triggered the grid’s protection system and the entire network to shut down in less than two minutes. It left several million people without power and cost the economy <a href="http://www.oecd.org/gov/risk/46891645.pdf">CAN$6 billion</a>. </p>
<p>Clearly there are risks for investment and retail banks, currency exchanges, investment funds, and insurance and real estate companies – which all rely on systems that are susceptible to space weather. To understand exactly how these risks manifest themselves, space weather experts have been coming together with those from the financial sector. From the discussions a realisation of just how many areas of these businesses could be affected emerged. A <a href="http://luciegreen.com/wp-content/uploads/2016/08/space_weather_and_finance.pdf">new report</a> shows where these impacts may be felt and gives guidelines on how businesses can build resilience when it comes to the threat of space weather.</p>
<h2>Understanding the risks</h2>
<p>The origin of space weather lies in the atmosphere of the sun, which generates strong winds, big bursts of radiation, including X-rays and UV (solar flares), and eruptions of electrically charged gas and magnetic field (coronal mass ejections). </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/136084/original/image-20160831-30762-1i0u789.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">
<figcaption>
<span class="caption">A coronal mass ejection from August 2012.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gsfc/7931831962/in/photolist-d5UHiu-nDePcB-5utymV-absVw6-dSDgae-bozyiY-97nyAt-4PnMyH-qaiCAK-awVaEv-pAwBok-8Chf6V-5e21hd-oqfcK2-8oC7N1-dyKu1P-qrKaYe-oUoA7k-dyKuX4-asBADA-qvvYiY-p7Pc2U-egcv1D-dtvHND-pvyZdV-ksysHk-dyKFkM-dtvHbg-7LQndv-ksLoo4-pvLg2g-bBeBbR-nY7r2k-cmkfV-qqyNm8-jCfMcP-KTiyQ-rhRoCb-bzakEj-dtBfWJ-jb2RnM-pLujVY-omgtsY-mCvZ48-araToX-cE76Ss-egifLq-bESXH-dyR2S9-pgV6G2">NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The <a href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1859MNRAS..20...13C&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf">first observation of a solar flare</a> was made more than 100 years ago in 1859. The <a href="http://adsabs.harvard.edu/abs/1972BAAS....4R.394T">discovery of coronal mass ejections</a> came much later, in the early 1970s. As well as emitting light and heat, the X-rays, high-energy particles and magnetic field that race towards the Earth disturb the Earth’s own magnetic field and, as well as generating beautiful auroras, induce electric currents where they may not be appreciated.</p>
<p>Lessons from the Hydro-Québec storm and the malfunctioning of satellites over the decades have helped us to understand the level of the risk there is from space weather and how to ward off its effects. National grids are being engineered to be more robust and daily space weather forecasts are issued for the hours and days ahead. The first step toward mitigating against the effects of space weather, is to keep track of it.</p>
<p>At a very basic level, a continuous and uninterrupted power supply is needed for the various systems that are used to make financial trading more profitable and our personal finances increasingly paperless. But during some extreme space weather events, showers of high-energy particles and the radiation from solar flares can affect key systems. This can hinder the processing of the extremely high volume of transactions – the transfer of stocks, shares or money for example. The synchronised timing of transactions is imperative and the time stamp often comes from global positioning satellites, the signals of which can be affected by space weather.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=555&fit=crop&dpr=1 600w, https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=555&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=555&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=698&fit=crop&dpr=1 754w, https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=698&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/136108/original/image-20160831-30790-ddw1gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=698&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 bright flash in the middle is a mid-level solar flare from the sun.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gsfc/15857850919/in/photolist-qaiCAK-awVaEv-dyKu1P-KTiyQ-qrKaYe-oUoA7k-dyKuX4-asBADA-qvvYiY-p7Pc2U-rhRoCb-bzakEj-egcv1D-dtBfWJ-dtvHND-pvyZdV-ksysHk-dyKFkM-dtvHbg-7LQndv-ksLoo4-pvLg2g-bBeBbR-nY7r2k-cmkfV-qqyNm8-jCfMcP-8rjYy5-jb2RnM-pLujVY-omgtsY-mCvZ48-araToX-cE76Ss-egifLq-bESXH-2YNBVy-dyR2S9-pgV6G2-pQZrk7-9iDfMp-oX69UY-8V9XY-jJqjHT-qvLFvb-bza9o5-csBTnw-dzfcpn-bBE2Q5-dURu2o">NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>At a more basic level, space weather can also affect air travel, an increasingly normal function of many businesses. The interruption it can cause to radio communications can cause flights to be disrupted, diverted or even cancelled. </p>
<p>Now that the vulnerabilities are being identified, a range of solutions can be developed. Companies have crisis management teams in place and space weather can be planned for, too. In-house exercises can be run to identify what space weather effects are important to each particular business, and processes can be built or extended accordingly.</p>
<p>So don’t be alarmed by space weather, but equally don’t forget its hidden influence over your day-to-day activities and the glitches in can cause in the technological systems we rely on.</p><img src="https://counter.theconversation.com/content/64621/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucie Green receives funding from the Royal Society and the Leverhulme Trust to investigate the causes of coronal mass ejections, and has received funding from ESA and the UK Space Agency to investigate the impact of space weather and concepts for space-based space weather monitoring.</span></em></p>Our growing dependency on satellites for all forms of communication has made the problem of space weather even more acute.Lucie Green, Professor of Physics, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/598482016-05-23T15:05:14Z2016-05-23T15:05:14ZSolar storms could solve longstanding paradox of how life on Earth arose<figure><img src="https://images.theconversation.com/files/123604/original/image-20160523-11025-1fpg4f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar flare on August 31, 2012.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>It was only a matter of 700m years or so after Earth formed and its surface cooled and solidified that life began to flourish on Earth. All studies suggest that life requires water – and we know from rocks on Earth that the climate in this distant past was sufficiently warm for liquid water to be present. But therein lies a mystery.</p>
<p>The young sun emitted only about 70% of the radiation it emits today, making it unlikely that it could have heated the Earth enough for liquid water to exist on the surface. But now <a href="http://nature.com/articles/doi:10.1038/ngeo2719">new research</a>, published in Nature Geoscience, suggests that the sun must have been a lot more active than we previously thought. The work has significant implications for theories about the production of the simple molecules required for life – on Earth and beyond. </p>
<p>The puzzle of how water could exist on the Earth’s surface at so early a time is dubbed <a href="http://science.sciencemag.org/content/177/4043/52.abstract?ck=nck">the faint young sun paradox</a> and has been debated for over 40 years. There have been many different solutions proposed, but they all require significant levels of greenhouse gases to be available in the early atmosphere. However, this is not entirely consistent with what has been observed in the geological record. For instance, the level of carbon dioxide (CO<sub>2</sub>) required in the atmosphere to enhance surface temperatures is <a href="http://www.earth.lsa.umich.edu/%7Ensheldon/Sheldon2006PCRes.pdf">greater than seems to have been present</a> based on evidence from fossil soils. Nevertheless, assuming that these gases were present, researchers have developed a number of <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2944365/pdf/cshperspect-ORI-a004895.pdf">computational models</a> outlining how atmospheric chemistry at the time could have helped kick-start life.</p>
<p>But the new research has gone about doing this modelling in a different way by changing the starting assumption about the sun’s activity. The sun was usually considered to be pretty similar to how it is today, apart from having a slightly lower heat flux. But the new study used data from the <a href="http://kepler.nasa.gov/">exoplanet-hunting mission Kepler</a>, which has also been recording the activity of different types of stars, to work out that this was probably not the case.</p>
<p>In fact, the number and frequency of solar flares from young sun-like stars seen by Kepler indicate that our newly-formed sun must have been much more active than previously thought. Although generally radiating at about 70% of its current level, the early sun would have been subject to frequent and violent solar flares or coronal mass ejections (CME). During such an event, there is the potential for the energetic particles emitted from the sun to power through <a href="https://theconversation.com/nasa-flies-satellites-through-explosion-in-space-and-starts-to-unravel-mystery-of-magnetism-59290">the magnetic field which usually protects the Earth</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123618/original/image-20160523-11020-132mn80.jpeg?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">
<figcaption>
<span class="caption">Stromatolites, believed to be the oldest life form on Earth, growing in Yalgorup National Park in Australia.</span>
<span class="attribution"><span class="source">C Eeckhout/wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>While there has only been one such recorded <a href="http://www.nasa.gov/topics/earth/features/sun_darkness.html">event in the past 30 years</a>, the researchers calculated that the young sun may have produced at least one CME per day that was in the direction of Earth. This means that the amount of energy dumped into the Earth’s atmosphere would have been sufficient to fuel a whole series of chemical reactions. </p>
<h2>The cocktail of life</h2>
<p>It is <a href="http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/rocks_metals/6_clean_air4.shtml">widely assumed</a> that the atmosphere at the time – as it is now – was dominated by nitrogen. The enhanced flux of energetic particles from the sun would split the relatively unreactive nitrogen molecule into two highly reactive nitrogen atoms. These could then go on to react with almost any molecule proposed to be in the early atmosphere – including carbon monoxide (CO), carbon dioxide (CO<sub>2</sub>), water (H<sub>2</sub>O), methane (CH<sub>4</sub>), ammonia (NH<sub>3</sub>) and others.</p>
<p>The final products of many of these reaction pathways are hydrogen cycanide (HCN) and nitrous oxide (N<sub>2</sub>O). The latter, also known as laughing gas, is a powerful greenhouse gas – important for allowing liquid water to exist. The former, hydrogen cycanide, is a key precursor molecule for the formation of amino acids. </p>
<p>In this way, the research solves the problems of maintaining the temperature of the Earth’s surface, and the production of a biologically-significant feedstock for life on Earth at the same time. The authors go on to suggest that a rain of other nitrogen-bearing molecules onto the surface would also provide fertiliser for a new biology.</p>
<p>The result is exciting and definitely a case of solving two problems for the price of one – with the bonus of it being applicable to some of the <a href="https://theconversation.com/more-than-1-000-new-exoplanets-discovered-but-still-no-earth-twin-59274">exoplanets being discovered by the Kepler Space Telescope</a>.</p><img src="https://counter.theconversation.com/content/59848/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Monica Grady receives funding from the STFC and EU Horizons 2020. She is a Trustee of Lunar Mission One and a member of the EUROCARES consortium.</span></em></p>Life on Earth may have started with a bit of sunshine and showers, followed with a light breeze of laughing gas and a sprinkle of hydrogen cyanide.Monica Grady, Professor of Planetary and Space Sciences, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/562752016-03-17T04:34:11Z2016-03-17T04:34:11ZWhat the ‘weather’ is like on a star can help in the search for life<figure><img src="https://images.theconversation.com/files/115379/original/image-20160317-30211-1m1jg4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artist’s illustration of Kappa Ceti whose stellar winds are 50 times stronger than our sun’s. Any Earth-like planet would need a magnetic field to protect its atmosphere if it was to stand a chance of hosting life.</span> <span class="attribution"><span class="source">M. Weiss/CfA</span></span></figcaption></figure><p>Scientists are studying the “weather” around young sun-like stars in an attempt to understand the conditions needed for a system to have planets that <a href="https://theconversation.com/what-makes-one-earth-like-planet-more-habitable-than-another-33479">would stand a chance of hosting life</a>.</p>
<p><a href="http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+20630">Kappa Ceti</a> is a relatively nearby star that <a href="http://www.solstation.com/stars/kap-ceti.htm">resembles our sun in its youth</a>, when it was just half-a-billion years old. But the <a href="http://arxiv.org/abs/1603.03937">results of a detailed study</a> of Kappa Ceti released overnight reveal a star far more violent and active than our modern-day sun.</p>
<p>When we look at stars in the night sky, we often imagine serene glowing balls of gas that will illuminate the universe for billions of years. </p>
<p>But stars give off more than just light. They shed material, continually flooding their environment with a <a href="http://astronomy.swin.edu.au/cosmos/S/stellar+winds">stellar wind</a>. They also emit vast explosions of material, <a href="http://hesperia.gsfc.nasa.gov/sftheory/flare.htm">flares</a> and <a href="http://solarscience.msfc.nasa.gov/CMEs.shtml">mass ejections</a>, continually flinging their outer layers into space.</p>
<p>This flood of material spewing from a star is known as <a href="http://spaceweather.com/">space weather</a> and, until recently, it has proven incredibly challenging for astronomers to study on any star other than the sun.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/115369/original/image-20160317-30203-x8blvm.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"></a>
<figcaption>
<span class="caption">Our sun burps, on August 31, 2012, flinging material into space as part of a coronal mass ejection.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gsfc/7931831962">Flickr/NASA Goddard Space Flight Centre</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Measuring a star’s activity</h2>
<p>An important question in astrobiology is: “how normal is our sun?”. Is our star unusual, with life an accidental beneficiary? Or are there other sun-like stars capable of hosting planets with life? </p>
<p>The problem is that stars are <a href="http://imagine.gsfc.nasa.gov/features/cosmic/nearest_star_info.html">very far away</a>. Even the <a href="http://hubblesite.org/newscenter/archive/releases/1996/04/image/a/">most powerful telescopes</a> can barely resolve the disks of even the largest stars. So how can we study the weather generated by those stars? </p>
<p>To do this, the scientists in the <a href="https://bcool.irap.omp.eu">BCool consortium</a> take advantage of the fact that stars, particularly active ones, have strong magnetic fields that are intimately tied to the star’s activity. </p>
<p>As light (an electromagnetic wave) passes through a strong magnetic field, it becomes polarised. The degree and type of polarisation depends on both the direction and the strength of the magnetic field. </p>
<p>It is this polarisation that the BCool scientists measure to study the magnetic fields of sun-like stars. They observe those stars in polarised light (a bit like putting polarised sunglasses on the telescope), which allows them to map the magnetic field on the surface of the star. </p>
<p>From this, they calculate how the field extends outward from the star, and how it evolves with time. This allows them to determine the stellar wind and to model the impact of that wind on any orbiting planets.</p>
<h2>A younger star</h2>
<p>Kappa Ceti is located 30 light-years from Earth, in the constellation of <a href="http://www.ianridpath.com/startales/cetus.htm">Cetus</a> (the Whale).</p>
<p>It is very similar to our sun – about as massive, as bright and as hot. But while our sun is very much middle-aged, Kappa Ceti is far younger. At between 400 and 800 million years old, Kappa Ceti is probably a good analogue for what our sun was like back when life was first getting a foothold on Earth. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=538&fit=crop&dpr=1 600w, https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=538&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=538&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=676&fit=crop&dpr=1 754w, https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=676&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/115201/original/image-20160315-25487-dmprma.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=676&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 computer model showing the magnetic field lines of Kappa Ceti (gray lines) looping out from the star’s surface. These magnetic fields generate a stellar wind 50 times stronger than our sun’s.</span>
<span class="attribution"><span class="source">TCD / A Vidotto Do Nascimento et. al (2016). ApJLetters</span></span>
</figcaption>
</figure>
<p>Similar to other young stars, Kappa Ceti has been found to be very magnetically active. Its surface is littered with large starspots – stellar acne resulting from the cooling effect of magnetic fields erupting through the stellar surface.</p>
<p>While our sun also has spots, those on stars such as Kappa Ceti are far larger and more numerous, the result of a much stronger magnetic field.</p>
<p>Such a strong magnetic field propels a stream of plasma (ionised gas) into space, with this stellar wind being 50 times stronger than that of our sun.</p>
<p>What would that mean for any planets around such a star? Would they be able to survive the onslaught?</p>
<h2>Stellar winds and atmospheres</h2>
<p>Stellar winds can be dangerous things. Without protection, a star’s wind can <a href="http://mars.nasa.gov/news/whatsnew/index.cfm?FuseAction=ShowNews&NewsID=1869">strip the atmosphere from a planet</a>, leaving it an airless husk. And a stronger wind poses more of a threat than a weaker one.</p>
<p>Fortunately, planets often come with their own shield, a magnetic field of their very own that can protect them from their host star’s worst excesses. </p>
<p>This is nicely seen here on Earth. The great majority of the solar wind is deflected around our planet. Only the most energetically flung particles break through, following the Earth’s magnetic field to the poles, where they trigger the beautiful Aurora Borealis and Australis.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/GW8o62mlQdo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>But would the Earth’s magnetic field stand up to a wind as strong as Kappa Ceti’s? The BCool team looked into this. It’s thought that when the Earth was young, its magnetic field was probably <a href="http://www.sciencedirect.com/science/article/pii/S003192019900103X?np=y">no stronger than it is today</a>. </p>
<p>As it turns out, our magnetic field would have been enough, even if our sun was once as active as Kappa Ceti. The Earth’s shield, the magnetosphere, would have been compressed, shrunk to about one-third its current size. But it would have endured, protecting Earth and allowing our planet to remain habitable.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=328&fit=crop&dpr=1 600w, https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=328&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=328&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=412&fit=crop&dpr=1 754w, https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=412&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/115396/original/image-20160317-30244-1j3fqth.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=412&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Artist’s rendition of Earth’s magnetosphere.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Mars, however, was not so lucky. It’s a smaller planet and its interior cooled more quickly than the Earth’s, quashing the internal dynamo that drives our planet’s magnetic shield.</p>
<p>Without a strong magnetic field, Mars was exposed to the full force of the sun’s youthful rage. Over the aeons, its atmosphere has been <a href="http://www.nasa.gov/press-release/nasa-mission-reveals-speed-of-solar-wind-stripping-martian-atmosphere/">slowly stripped away</a>. At the same time, the remains were drawn down, chemically trapped in the planet’s surface. </p>
<p>The result is a frigid, arid world, with an atmosphere just a tenuous wisp of its former glory. </p>
<h2>The search for life out there</h2>
<p>Astronomers should soon begin to discover the first truly Earth-like planets orbiting other stars, and the race will be on to search for evidence of life upon them. But where should we look? </p>
<p>To choose the most promising targets, those scientists will have to consider the many factors that can make one planet more liveable than another. So the <a href="https://theconversation.com/for-life-to-form-on-a-planet-it-needs-to-orbit-the-right-kind-of-star-33477">nature of the planet’s host star</a> will play a vital role.</p>
<p>By studying stars such as Kappa Ceti, we are building an understanding of how stars and planets interact. Once those first exo-Earths are found, it will be possible to measure and characterise the winds of their host stars. This will then help us determine which of those planets to target in the search for life elsewhere.</p><img src="https://counter.theconversation.com/content/56275/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 organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In the search for life on other planets in the universe we need to find the right kind of star, and it needs to have the right kind of space weather.Jonti Horner, Vice Chancellor's Senior Research Fellow, University of Southern QueenslandStephen Marsden, Senior Lecturer (Astronomy), University of Southern QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/508872015-11-23T12:44:16Z2015-11-23T12:44:16ZNew early-warning system could protect Earth from explosive space weather<figure><img src="https://images.theconversation.com/files/102814/original/image-20151123-18230-woh9v1.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.flickr.com/photos/gsfc/6819077978">NASA Goddard Space Weather Center</a></span></figcaption></figure><p>The sun can erupt with flares more energetic than 30 billion times the yield of all nuclear weapons <a href="https://books.google.co.uk/books?id=xAwAAAAAMBAJ&lpg=PA63&dq=510.3&as_pt=MAGAZINES&pg=PA61#v=onepage&q=510.3&f=false">ever detonated</a>. The energetic particles released by solar flares tunnel a path through our inner solar system with speeds regularly exceeding 6 million kph. If the Earth is unfortunate enough to sweep through the path of these particles, they can cause catastrophic problems by acting like bullets of radiation, damaging electrical and electronic equipment.</p>
<p>Experts have warned that even a single monster solar flare could cause <a href="http://www.inquisitr.com/2550342/white-house-prepares-for-massive-solar-storm-that-could-cause-2-trillion-in-damages/">up to US$2 trillion worth of damage on Earth</a>. This could include the loss of communication and navigation satellites and electricity grids. Dangers to human life and health could follow.</p>
<p>With this in mind, it is no wonder space weather has now been added as one of the greatest dangers to life on Earth in the <a href="https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/419549/20150331_2015-NRR-WA_Final.pdf">UK’s national risk register</a>, only fractionally behind terrorist attacks. It’s paramount that we study the behaviour of the sun so we can create an early-warning system to alert of us impending danger from this kind of space weather.</p>
<h2>Destructive solar flares</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102818/original/image-20151123-18227-3he8cs.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">
<figcaption>
<span class="caption">Sunspot:Earth ratio.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Solar flares’ incredibly destructive power comes from the magnetic fields that are visible across the sun’s entire surface but are most concentrated within regions called sunspots. These spots can be huge, some many times bigger than the Earth, with magnetic field strengths thousands of times more intense than those in the surrounding “quiet” parts of the sun.</p>
<p>As these strong magnetic fields leave the surface of the sun, they extend upwards many thousands of kilometres into the corona, the region of the sun’s atmosphere visible during total solar eclipses. Here they shape the charged particles (plasma) of the corona into giant loop-like structures. The physical strength of the magnetic field lines at the top of these loops is 100 times smaller than similar regions on the solar surface, but the loops still possess immense energy that can twist and shear.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102828/original/image-20151123-18267-16f8911.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">
<figcaption>
<span class="caption">What a flare up.</span>
<span class="attribution"><span class="source">NASA/SDO</span></span>
</figcaption>
</figure>
<p>Constant buffeting from the underlying atmosphere adds tension to the magnetic field loops, similar to an elastic band being stretched. Scientists believe that when the loops restructure themselves to release this tension they give off a huge blast of electromagnetic energy into space, creating a <a href="http://hesperia.gsfc.nasa.gov/sftheory/flare.htm">solar flare</a>.</p>
<h2>New imaging method</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=841&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=841&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=841&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1057&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1057&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102826/original/image-20151123-18255-fujln5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1057&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dunn Solar Telescope.</span>
<span class="attribution"><span class="source">QUB</span></span>
</figcaption>
</figure>
<p>My colleagues and I, working with an international team of researchers, have devised a high-precision way of studying the sun’s atmosphere that is up to ten times faster than previous methods. Using images of all layers of the Sun’s atmosphere taken by specialist telescopes on Earth and in space, we have discovered a wealth of compressible waves similar to sound waves travelling along the magnetic loops. We believe these are caused by vibrations close to the solar surface that are initially trapped within the turbulent layers of <a href="http://soi.stanford.edu/press/ssu8-97/pmodes.html">the sun’s interior</a> before leaking outwards towards the visible surface.</p>
<p>The speed of these waves, which can reach 800,000 kph, depends on the characteristics of the sun’s atmosphere, including its temperature of around 1,000,000°C and the strength of its magnetic field. Studying the wave speed and temperature at different locations in the Sun’s atmosphere at any given time allows us to calculate the magnetic field strength at that point. So by studying how the magnetic field changes on very short timescales, we have the potential to identify the precursors responsible for solar flares and space weather.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/1kSx7AOwEco?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Our new method, <a href="http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3544.html">which we describe</a> in the journal Nature Physics, can uncover changes in coronal magnetism within around one minute. This is a dramatic improvement on previous direct imaging approaches that often required exposure times exceeding one hour to be able to extract the faint magnetic signals. This means we have a much faster way of examining magnetic field changes in the lead up to solar flares. Ultimately, this could be used to provide advanced warning against such violent space weather.</p>
<p>Our next goal is to fully automate the processes so we can continually monitor the Sun’s coronal magnetic fields in real-time. We hope to use software with artificial intelligence to study the large amount of data this produces and learn why, how, and ultimately when solar flares will erupt. This may not necessarily protect us from the resulting onslaught but it will provide us with crucial advanced warning. This could buy us enough time to minimise the damage associated with 100 billion kilograms of solar “bullets” speeding towards Earth at over 6 million kph.</p><img src="https://counter.theconversation.com/content/50887/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Jess receives funding from the UK's Science and Technology Facilities Council (STFC).</span></em></p>Researchers have found out how to predict solar flares up to ten times faster than previous methods.David Jess, Lecturer and STFC Ernest Rutherford Fellow, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/440982015-07-27T10:18:45Z2015-07-27T10:18:45ZThe scorching winds on the surface of the sun – and how we’re forecasting them<figure><img src="https://images.theconversation.com/files/86837/original/image-20150630-5819-1v65yze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tempestuous times on the solar surface.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Activity_Continues_On_the_Sun.jpg">NASA</a></span></figcaption></figure><p>The most extreme weather of all rarely gets a mention, even in the UK where we’re famous for our weather talk. Far above our heads the Earth is regularly hit by colossal, tsunami-like waves of scorching gas and savage, supersonic winds from space. </p>
<p>The culprit for this extra-terrestrial weather is sat at the centre of our solar system. The familiar pictures of our Sun that portray a plain, incandescent orb, serenely holding the planets in place, couldn’t be further from the truth. The Sun is a rowdy place.</p>
<p>One of the most spectacular forms of space weather are <a href="http://solarscience.msfc.nasa.gov/CMEs.shtml">Coronal Mass Ejections</a>, where the Sun sporadically throws out billions of tonnes of hot gas and magnetic field into space. </p>
<p>The Sun also generates its own wind, which ranges from “breezes” to “hurricanes”. It’s all on a much bigger scale though – even average solar winds are much more ferocious than anything we could ever experience, with speeds varying between a gentle 500,000 miles per hour to a gusty 2,000,000 mph. </p>
<p>These winds carry with them a part of the Sun’s atmosphere, a million-°C gas composed of highly energetic electrons, protons and alpha particles. The winds are accelerated along the sun’s outstretched, <a href="http://www.windows2universe.org/glossary/IMF.html">tentacle-like magnetic field</a>, which originates deep under its surface and extends out past Earth to the edges of the solar system.</p>
<p>Being able to forecast the solar wind has its problems though. For example, we know they predominantly originate in darker, less dense patches of the Sun’s atmosphere known as <a href="http://www.spaceweatherlive.com/en/help/what-is-a-coronal-hole">coronal holes</a>, however we are still <a href="http://www.nature.com/ncomms/2015/150106/ncomms6947/full/ncomms6947.html">unable to locate</a> the other significant sources that must contribute to the wind. More importantly, we don’t have a clear explanation of how the winds are heated and accelerated.</p>
<h2>Blowin’ in the wind</h2>
<p>My colleagues and I were interested in the processes underlying these tempestuous winds. In a study published in the journal <a href="http://www.nature.com/ncomms/2015/150727/ncomms8813/full/ncomms8813.html">Nature Communications</a>, we investigate powerful magnetic waves, known as <a href="http://www.sciencedaily.com/releases/2011/08/110801094253.htm">Alfvén waves</a>, located in the regions where the solar wind originates. These waves cause the Sun’s magnetic field to violently sway back and forth at tens of thousands of miles per hour, transporting energy around the star’s atmosphere and out into space.</p>
<p>It is this role as a magnetic energy carrier that means the Alfvén waves are often responsible for accelerating the solar wind to such monstrous speeds. We found that some of the necessary conditions exist for the waves to break down their energy to smaller scales and supply some of it to the wind (potentially via the interactions of the waves with particles) – <a href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26A...270..304V&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf">something predicted for a couple of decades</a> but never observed. Future studies of Alfvén waves should reveal how much energy they feed to the solar wind and may even allow us to forecast wind speeds. </p>
<figure>
<iframe src="https://player.vimeo.com/video/132308622" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Sun’s magnetic field swaying at 30,000 mph due to Alfvén waves. The white line is for scale and represents 30,000 miles (roughly four times the Earth’s diameter).</span></figcaption>
</figure>
<h2>Why you should care</h2>
<p>“Space weather forecasts” may seem like one for the future but such reports are already used by a host of agencies. The UK’s National Grid, for instance, relies upon daily updates to avoid overloads of the electrical grid due to resulting geomagnetic storms (an <a href="http://www.scientificamerican.com/article/geomagnetic-storm-march-13-1989-extreme-space-weather/">extreme case in 1989</a> cut off power for six million people in Quebec).</p>
<p>We don’t often encounter the consequences of space weather in our day-to-day lives, but as society becomes increasingly dependent on technology it will surely be felt more keenly. Recent reports have demonstrated how wide-ranging this can be, for example, <a href="https://theconversation.com/bad-space-weather-may-have-caused-fatal-afghan-gun-battle-32081">disrupting radio communications</a>, damaging satellites and causing <a href="http://www.raeng.org.uk/publications/reports/space-weather-full-report">increased radiation levels</a> on commercial flights. The UK government is concerned enough that space weather was added to the <a href="https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/419549/20150331_2015-NRR-WA_Final.pdf">National Risk Register</a> and, in late 2014, it set up the <a href="http://www.metoffice.gov.uk/publicsector/emergencies/space-weather">Met Office Space Weather Operations Centre</a> to monitor it and provide an assessment of the risks.</p>
<p>Looking forward, if we are to regularly engage in space tourism, asteroid mining or manned trips to other worlds, then travellers and technology will be exposed to the elements once they <a href="http://www.exploratorium.edu/spaceweather/magneto.html">leave the safety</a> of Earth’s protective magnetic field. While space weather may be hazardous, there are some suggestions we can <a href="http://www.lunarsail.com/LightSail/msit.pdf">exploit the solar wind to power spacecraft</a> using magnetic or electric sails or even harvest some of its energy using a so called <a href="http://www.newscientist.com/article/dn19497-outofthisworld-proposal-for-solar-wind-power.html#.VXfwDDdZWFU">Dyson-Harrop satellite</a>.</p>
<p>Our findings are an example of one of the many advances being made in understanding the origins of space weather, although much more is needed to bring our predictive abilities in line with those of our meteorological friends. Space weather forecasters will also need to continue popularising the lexicon of extra-terrestrial weather and raising awareness of its impact here on Earth. Then, maybe one day, people will tune in to the morning’s space weather report to see whether they should take that trip to Mars.</p><img src="https://counter.theconversation.com/content/44098/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Morton works for Northumbria University. He receives funding from The Leverhulme Trust. He is affiliated with the Royal Astronomical Society.</span></em></p>It’s the windiest place in the entire solar system – and these storms can be felt here on Earth.Richard Morton, Leverhulme Trust Fellow in Mathematics, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/426692015-06-02T05:13:29Z2015-06-02T05:13:29ZOur predictions of solar storms have not been very accurate until now – here’s why<figure><img src="https://images.theconversation.com/files/83573/original/image-20150601-6955-o0s5r0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ain't half hot: but where's it heading?</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=143317899095022600000&searchterm=solar%20storm&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=209449732">Naeblys</a></span></figcaption></figure><p>When a space hurricane was unleashed from the sun on January 7 2014, space-weather centres around the world <a href="http://www.space.com/24201-sun-unleashes-major-solar-flare-video.html">sent out warnings</a>. The hurricane was heading directly for Earth and was predicted to produce a strong geomagnetic storm. But then an unexpected thing happened: the storm bypassed Earth and headed for Mars instead. It confirmed that our techniques for predicting such events are not as accurate as we would like. I am one of the co-authors of a <a href="http://www.nature.com/ncomms/2015/150526/ncomms8135/full/ncomms8135.html">new paper that provides</a> an insight into why the predictions were wrong and what we can do about this in future. </p>
<p>Space storms are a regular part of our sun’s activity. These so-called coronal mass ejections are a by-product of dramatic events called solar flares. They happen in active regions of the sun where a great amount of energy is built up in the form of a tangled magnetic field. This acts like a rubber band that has been twisted too far, snapping as it releases its stored energy.</p>
<p>The geomagnetic storms that occur when these ejections hit Earth can have dramatic consequences. Beautiful auroras in the night sky might be sights to behold, but equally GPS and telecommunication systems that rely on satellites can be disrupted, while radio black-outs can make it necessary to re-route air travel. In the worst scenarios, there can be strong surges of electrical currents that cannot be supported by national electric grids. This can lead to major power outages, such as the one <a href="http://www.nasa.gov/topics/earth/features/sun_darkness.html">experienced by</a> Montreal and the Quebec region in Canada in March 1989.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/KqXtwAZFfUQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Our findings</h2>
<p>The progress of the January 2014 solar flare in the sun’s atmosphere was monitored by the Solar Dynamics Observatory, a NASA mission launched in 2010 dedicated to our hosting star. Our research team, which was lead by <a href="http://www.iwf.oeaw.ac.at/en/institute/staff/staff/?tx_smemployeelist_pi1%5BempID%5D=1810">Dr Christian Möstl</a> from the Austrian Academy of Sciences, analysed the regions surrounding the storm’s original location on the sun. </p>
<p>We found that the area surrounding it on one side was another intensely active region with a strong magnetic field, while the other side was occupied by a weak magnetic field called a “coronal hole”. The team concluded that the former strong field pushed the erupting storm away, channelling it into the weak field path and away from its original route. </p>
<p><strong>The flare behind the storm</strong></p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/wxBRwOY7BQA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Once the storm was on its way out into space, it was then recorded by several space probes, including the <a href="http://www.srl.caltech.edu/ACE/">Advanced Composition Explorer</a> in Earth’s orbit and the <a href="http://www.nasa.gov/mission_pages/msl/index.html">Curiosity Rover on Mars</a>. In particular, the Martian robot reported a decrease in the cosmic rays in its vicinity, the so-called <a href="http://www.britannica.com/EBchecked/topic/213051/Forbush-effect">Forbush effect</a>. This phenomenon takes place when the magnetic field of the solar cloud deflects the energetic particles, originating from outer space, which constantly bombard a planet. </p>
<p>This data helped our team to build a model to reproduce the evolution of the solar cloud in space, and hence its arrival times, both at Earth and at the red planet. This should improve the models that scientists use for making real-time forecasts of space weather, such as those used by the <a href="http://www.metoffice.gov.uk/publicsector/emergencies/space-weather/met-office-role">UK MET Office space weather prediction centre</a>, which opened in October 2014.</p>
<p>In short, we reached two conclusions. For accurate forecasts, we will have to monitor the surroundings of the point of origin of the solar activity in future, since these appear to strongly dictate how coronal mass ejections develop. This will ultimately tell us whether a coronal mass ejection will hit the Earth, at which angle and with what intensity. </p>
<p>Second, it is highly important that we continue to improve our models for describing how solar storms evolve once they leave the sun. This is what allows us to predict their arrival times at Earth, enabling national authorities to prepare for their consequences as accurately as possible. To do this, much more research is still required into areas such as the mechanisms underlying the ejection of solar storms, how they evolve in space and how they interact with a planet’s natural magnetic shields. That is a key challenge for my field in the coming months and years.</p><img src="https://counter.theconversation.com/content/42669/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Miho Janvier 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>Astrophysicists found out after the January 2014 solar flare that their predictions of solar weather were not very accurate. Here’s the fix (kind of).Miho Janvier, Lecturer in Mathematics, University of DundeeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/347502014-12-04T01:12:25Z2014-12-04T01:12:25ZPredicting daily space weather will help keep your GPS on target<figure><img src="https://images.theconversation.com/files/65806/original/image-20141128-9769-1m9h9c5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">GPS is used in many devices to help us navigate.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/daveynin/6067262367">Flickr/daveynin </a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>It’s well known that severe space weather events – which are quite rare – can have a negative impact on our use of Global Positioning System (<a href="https://theconversation.com/explainer-what-is-gps-12248">GPS</a>) enabled devices. But our research, published in <a href="http://onlinelibrary.wiley.com/enhanced/doi/10.1002/2014GL062203/">Geophysical Research Letters</a>, shows that another form of space weather – which occurs on a daily basis – can cause problems for GPS too.</p>
<p>Knowing how to predict – or forecast – these daily space weather events is the key to protecting those people and industries who rely on GPS.</p>
<p>The awareness and use of the GPS has dramatically increased over the past few decades, no doubt in part due to the availability and affordability of in-car satellite navigation systems and GPS-capable smart phones.</p>
<p>But the use of GPS in industries in Australia, including agriculture, mining and construction, has also dramatically increased and is <a href="http://www.acilallen.com.au/cms_files/ACIL_GNSS_positioning.pdf">expected</a> to boost the nation’s economy by up to A$13.7-billion by 2020. </p>
<p>This increased use and reliance on GPS in particular has actually increased our society’s vulnerability to space weather. As detailed in other online <a href="https://theconversation.com/divert-power-to-shields-the-solar-maximum-is-coming-11228">articles</a>, space weather influences our use of many space-based technologies and assets around the world.</p>
<h2>Disturbances in the ionosphere</h2>
<p>A common, but much less reported, aspect of space weather is a plasma disturbance that occurs in the Earth’s ionosphere during the night-time hours, called equatorial plasma bubbles.</p>
<p>As the name suggests, <a href="http://www.insidegnss.com/auto/julyaug09-kintner.pdf">these disturbances</a> take place in the vicinity of the magnetic equator, such as South East Asia and Northern Australia. In some longitude sectors, such as across Africa, these plasma bubbles occur almost every night all year round.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/65653/original/image-20141127-4225-hwo9qz.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">
<figcaption>
<span class="caption">Numerical model representation of scintillation-causing equatorial plasma bubbles, low density regions (black) rising into the high-density plasma (red). The plasma waves generated by these bubbles affect radio waves that travel through them.</span>
<span class="attribution"><span class="source">John Retterer/Boston College</span></span>
</figcaption>
</figure>
<p>The process responsible for the onset of these ionospheric disturbances does not involve energetic explosions on the sun’s surface, like the commonly known <a href="http://www.space.com/24199-biggest-solar-flares-photos-2014-sun-storms.html">solar flares</a> and <a href="https://theconversation.com/solar-eruption-could-help-earth-prepare-for-technology-melt-down-18747">coronal mass ejections</a>. Instead, plasma bubbles are internally driven disturbances in the ionosphere that happen on a day-by-day basis. </p>
<p>After sunset, low electron density plasma from the lower ionosphere rises up into the high electron density plasma in the upper ionosphere, similar to a light fluid rising into a heavy fluid. This process is known as the Generalised <a href="https://theconversation.com/bad-space-weather-may-have-caused-fatal-afghan-gun-battle-32081">Rayleigh-Taylor instability</a>. The steep gradients at the edges of the bubble generates plasma waves, or turbulence.</p>
<h2>A break in the signal</h2>
<p>This turbulence scatters radio waves that travel through it, such as the radio signals used in satellite communications, and in the positioning, timing and navigation of GPS.</p>
<p>The result on the ground is that the received signal begins to randomly fluctuate in amplitude and phase (an effect called <a href="http://www.ips.gov.au/Satellite/6/3">ionospheric scintillation</a>) and becomes unrecognisable by the receiver.</p>
<p>This regularly causes the satellite-to-ground radio link to become completely severed. When using GPS, this only really becomes a problem when the receiver loses several satellites simultaneously, which is common at locations close to the magnetic equator because of these plasma bubbles.</p>
<p>But in the cases where only one satellite is being used, such as satellite communications, losing lock on the primary satellite has obvious negative implications.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/65808/original/image-20141128-9764-1ltcohw.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">GPS is only rendered useless when it loses contact with several satellites at the same time, which can happen when near equatorial plasma bubbles.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/mmartimo/3623343867">Flickr/daveynin</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>A <a href="http://onlinelibrary.wiley.com/doi/10.1002/2014SW001081/abstract">recent study</a> investigated the potential impact of plasma bubbles in an event when radio communications failures occurred during a fatal engagement between US combat soldiers and Taliban fighters in Afghanistan.</p>
<p>Due to the broad radio frequency range affected by these plasma disturbances, affected applications also include other forms of satellite signals and communications; for example, satellite cellular communications and television broadcasting.</p>
<h2>Forecasting the bubbles</h2>
<p>Currently, there does not exist a non-experimental and openly available model or online product that informs people of potential GPS disruptions due to plasma bubbles. This is largely because there is still a lot that we do not understand about these disturbances.</p>
<p>Scientifically, the seasonal behaviour of plasma bubbles is relatively well understood, but why they happen on one day and not the next is still a significant and ongoing challenge in ionospheric physics.</p>
<p>As such, a key research goal within this particular field is to develop a reliable day-to-day space weather forecasting capability specifically for plasma bubbles, in a similar manner to the traditional “rainy day” forecasts given by meteorologists.</p>
<p>Our study used an artificial neural network (ANN) prediction algorithm, which is a self-learning program that is trained using a given dataset of several parameters.</p>
<p>In this case, those parameters were several solar wind quantities measured by the <a href="http://www.srl.caltech.edu/ACE/">Advanced Composition Explorer</a> spacecraft, which is located at the <a href="http://www.esa.int/Our_Activities/Operations/What_are_Lagrange_points">Lagrangian point L1</a> between the sun and the Earth. The <a href="http://onlinelibrary.wiley.com/doi/10.1029/2004JA010500/abstract">algorithm</a> used this data to predict the level of geomagnetic activity resulting from the solar wind measured.</p>
<p>Outputs from this prediction algorithm were combined with physics-based upper atmospheric modelling to attempt to predict the onset of these disturbances.</p>
<p>We were able to show up to 95% accuracy in plasma bubble prediction, potentially giving anyone affected by ionospheric scintillation a number of hours notice of potential disruptions. With such forecasts, people and industries relying on GPS will be able to plan and account for these disruptions before they occur.</p>
<h2>Some geomagnetic activity is useful for GPS</h2>
<p>Our results also showed that common and low-intensity <a href="http://www.nasa.gov/mission_pages/sunearth/news/storms-on-sun.html#.VHaLDHVdXfE">geomagnetic storms</a>, which are associated with plasma disturbances from the sun’s surface, can effectively stop the equatorial plasma bubbles from ever growing and causing disruptions on GPS.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/_8yPQEE2Dnk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>This is important because during the peak bubble seasons (from February to April and from August to October in the Australasian region), the conditions are ripe for plasma bubble growth everyday.</p>
<p>We showed that geomagnetic storms change the global upper atmospheric wind system in a way that prevents the bubbles from growing at the equator during these periods, and this was well supported by our GPS observations.</p>
<p>These geomagnetic disturbances from the sun stop the bubbles from growing, and therefore provide opportunities for people to continue to use GPS at night-time during these peak plasma bubble seasons.</p>
<p>So, for those who use GPS at low-latitude locations – including in South-East Asia, the Pacific, South America and Africa – a geomagnetic disruption from the sun will actually help to stop GPS scintillation events after sunset at times of the year when scintillation events normally occur every night.</p><img src="https://counter.theconversation.com/content/34750/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Carter receives funding from the Victorian Postdoctoral Research Fellowship Program and the Australian Research Council.</span></em></p>It’s well known that severe space weather events – which are quite rare – can have a negative impact on our use of Global Positioning System (GPS) enabled devices. But our research, published in Geophysical…Brett Carter, Postdoctoral Researcher in Space Weather and Ionospheric Physics, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/340022014-11-11T19:29:36Z2014-11-11T19:29:36ZGiant sunspot returns – and it’s bigger and badder than ever<figure><img src="https://images.theconversation.com/files/64107/original/gsz4d9ct-1415599731.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ten Earths could be laid across the diameter of the gigantic sunspot in AR2191 during its previous rotation – captured on October 23, 2014.</span> <span class="attribution"><a class="source" href="http://www.nasa.gov/content/goddard/largest-sunspot-of-solar-cycle/#.VGBWKVOUcWd">NASA’s Solar Dynamic Observatory </a></span></figcaption></figure><p>The largest sunspot seen in 24 years is rotating back to face the Earth, and it looks to have grown even bigger.</p>
<p>Last month, the solar active region known as AR12192 (also known as AR2192 to some of its friends) <a href="http://www.iflscience.com/space/jupiter-sized-sunspot-largest-24-years">entertained the world</a> with the sunspot clearly visible with the naked eye (with some appropriate and approved solar-watch or eclipse dark glasses, of course), and produced a series of large flares.</p>
<p>But after spending some time over on the far side of the sun, it hasn’t finished impressing us yet.</p>
<p>AR12192 is due to rotate back onto our side of the sun today (November 12) and and it has grown. Because of its size, the leading edge would actually have appeared about a day earlier.</p>
<p>Charles Lindsey, of North West Research Associates (NWRA) in Boulder Colorado (and a frequent visitor to Monash University in Australia), has been following the progress of AR12192 since it disappeared around the west limb of the sun a couple of weeks ago, and found that it has grown significantly. </p>
<p>The sun rotates about once every 27 days as viewed from the Earth, so we haven’t been able to see AR12192 directly since then. But using the helioseismology technique <a href="https://www.cora.nwra.com/%7Edbraun/reprints/lb00.pdf">acoustic holography</a> that Dr Lindsey and his colleague Doug Braun developed, they can “see” large active regions on the far side by <a href="https://www.cora.nwra.com/%7Edbraun/reprints/fsi_science.pdf">computationally regressing oscillations</a> (waves) observed on the nearside back to their sources.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=233&fit=crop&dpr=1 600w, https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=233&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=233&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=293&fit=crop&dpr=1 754w, https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=293&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/64110/original/tpq5vwrn-1415600752.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=293&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Far side image of AR12192 in the yellow tinted section which we only ‘see’ using helioseismology.</span>
<span class="attribution"><a class="source" href="http://jsoc.stanford.edu/data/farside/">Stanford University’s Joint Science Operations Center</a></span>
</figcaption>
</figure>
<p>Drs Lindsey and Braun’s far side imaging technique is now routinely used to keep an eye on active regions popping up or developing on the other side of the sun. The image (above) shows a seismic reconstruction of the far side (in yellow) with a very clear and very large active region in the southern hemisphere. This is AR12192.</p>
<h2>Why all the activity?</h2>
<p>So, what is an active region, and how does it relate to sunspots? Active regions are huge agglomerations of magnetic field that bubble up to the surface from deep in the sun’s interior.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/yXYrLJCA9DQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Sunspots are the areas of strongest field, up to about 3,000 Gauss. To put that in context, the Earth’s magnetic field is around half a Gauss.</p>
<p>The magnetic field largely inhibits the boiling convection normally seen across the solar surface. Convection is the mechanism that carries most of the energy from the nuclear furnace in the core through the outer 29% of the sun.</p>
<p>That is why sunspots appear dark; magnetism halts the conveyor belt.</p>
<p>The sun is currently near the maximum of Solar Cycle 24 – the 24th cycle of solar activity since detailed recording began in 1755. Sunspot number rises and falls on a roughly 11-year cycle, and although Cycle 24 is very weak compared to others in the last century, it can still produce a doozy of a spot. </p>
<p>But active regions don’t just give us sunspots. They also produce flares, the most energetic events in the solar system.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=436&fit=crop&dpr=1 600w, https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=436&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=436&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=548&fit=crop&dpr=1 754w, https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=548&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/64111/original/3c2k9rct-1415601587.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=548&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 bright light in the centre of the image shows an X-class solar flare on October 26, 2014. This was the third X-class flare in 48 hours.</span>
<span class="attribution"><a class="source" href="http://www.nasa.gov/content/goddard/sunspot-ar2192-release-x2.0-class-solar-flare-on-oct-26-2014/#.VGBdpVOUcWd">NASA’s Solar Dynamic Observatory</a></span>
</figcaption>
</figure>
<p>Flares occur when the complex magnetic field twists and stretches to such an extent that it snaps, like a rubber band breaking, and then reconnects to other field lines.</p>
<p>This releases huge bursts of energy over several minutes, up to 6×10<sup>25</sup> Joules for the largest X-class flares. This is about 100,000 times the total energy usage of humans in a full year.</p>
<p>Coronal mass ejections (<a href="http://solarscience.msfc.nasa.gov/CMEs.shtml">CMEs</a>) also commonly emerge from active regions. These are massive bubbles of gas, weighing as much as 100 billion kg, that burst into space at up to 1,000 km per second, carrying huge loads of charged particles and magnetic flux.</p>
<p>CMEs are often – though not always – associated with flares, and flares may or may not have accompanying CMEs. A flare that doesn’t is termed “ordinary”.</p>
<p>On its first pass, the huge AR12192 was comparable in size to Jupiter and produced several (ordinary) <a href="http://www.nasa.gov/mission_pages/sunearth/news/X-class-flares.html#.VGFCDFOUcWc">X-class flares</a> and many smaller ones, but no large CMEs.</p>
<p>But Hugh Hudson of Space Sciences Laboratory at Berkeley, California, notes that older active regions tend to produce more CMEs, so he is expecting a big CME show this time around.</p>
<h2>Impact on Earth</h2>
<p>But what does this mean for us on Earth? CMEs in particular can have a massive impact on the Earth’s magnetosphere, causing stunning aurorae, power blackouts, interruptions to telecommunications and damage to satellites in orbit.</p>
<p>The so-called Carrington flare of 1859 produced aurorae visible in Queensland, and damaged telegraph stations around the world. Our modern technological world is far more vulnerable.</p>
<p>So, if AR12192 launches any large CMEs in our direction when it comes around to our side, we’d better batten down the hatches.</p>
<p>That can mean disconnecting long-distance power grids, placing satellites in safe mode and rerouting aircraft on polar routes.</p><img src="https://counter.theconversation.com/content/34002/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Cally has previously received funding from the Australian Research Council.</span></em></p>The largest sunspot seen in 24 years is rotating back to face the Earth, and it looks to have grown even bigger. Last month, the solar active region known as AR12192 (also known as AR2192 to some of its…Paul Cally, Professor of Solar Physics, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/315602014-09-11T02:59:32Z2014-09-11T02:59:32ZPrepare yourself – wild solar weather ahead<p>During the early hours of this morning (3:42am AEST) our sun released a strong solar flare. It follows right on the heels of a more moderate flare that was released from the same region of the sun on Tuesday morning.</p>
<p>But the sunspot that produced both flares, designated AR2158, was directly facing Earth when the latest flare was emitted so there’s likely to be some wild solar weather impacting Earth over the coming days.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58728/original/zh6xrrfz-1410397785.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">The Solar Dynamics Observatory captured the bright solar flare in ultraviolet light.</span>
<span class="attribution"><span class="source">NASA/SDO</span></span>
</figcaption>
</figure>
<p>Solar flares are ranked into three categories of intensity: X-class flares are the strongest; M-class are moderate; and C-class are the mildest. Today’s solar flare is ranked as an X1.6 class flare, the ‘1.6’ denoting that it is on the low end of the X-class category.</p>
<p>Such flares can trigger <a href="http://www.nasa.gov/mission_pages/sunearth/news/storms-on-sun.html">major events for Earth</a> such geomagnetic storms, solar radiation storms and radio blackouts. And <a href="http://spaceweather.com/">spaceweather.com</a> has reported that some high-frequency radio blackouts and other communication disturbances have already occurred as a result of this flare. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58731/original/wm9myrhr-1410398479.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">The sunspot AR2158 is the large dark region towards the centre of the Sun.</span>
<span class="attribution"><span class="source">NASA/SDO</span></span>
</figcaption>
</figure>
<h2>Eruptions from the sun</h2>
<p>A <a href="http://astronomy.swin.edu.au/cosmos/S/Solar+Flare">solar flare</a> is just one kind of eruption from the sun. It releases intense light, along with some radiation consisting of protons and other charged particles.</p>
<p>Often associated with flares is an even bigger eruption known as a coronal mass ejection (<a href="http://solarscience.msfc.nasa.gov/CMEs.shtml">CME</a>). In this case, as well as radiation, a gigantic bubble of gas is also blown off the sun.</p>
<p>The Solar and Heliospheric Observatory (<a href="http://sohowww.nascom.nasa.gov/">SOHO</a>) has captured CMEs released by both solar flares.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58733/original/42zbz42v-1410398826.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">Today’s solar flare produced a fast moving coronal mass ejection.</span>
<span class="attribution"><span class="source">NASA/ESA/SOHO</span></span>
</figcaption>
</figure>
<p>Tuesday’s flare, which was classified as an M4-flare, produced a bright CME which was <a href="http://www.spaceweather.com/images2014/09sep14/cme_anim.gif?PHPSESSID=qa2d9aeklmbeh01og45vvhd3m4">caught streaming out</a> of the sun at nearly 1,000 km/s. While today’s flare was <a href="http://www.spaceweather.com/images2014/10sep14/cme_anim.gif?PHPSESSID=qa2d9aeklmbeh01og45vvhd3m4">incredibly fast moving</a>, speeding along by as much as 3,750 km/s. </p>
<h2>Storms of a different kind</h2>
<p>The radiation released by the solar flare and corresponding CME flows down towards Earth to produce a solar radiation storm. </p>
<p>Fortunately, the Earth’s magnetic field and atmosphere blocks this radiation, so it doesn’t make its way down to us or affect airplane passengers. </p>
<p>Even the astronauts on board the ISS are safely inside the Earth’s magnetosphere and just in case, there are protected areas on the spacecraft where astronauts can ride out the storm. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/OvEKT8X3Bko?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">NASA captured a mid-level solar flare on 24 August 2014.</span></figcaption>
</figure>
<p>But solar radiation storms can affect satellites outside of the magnetosphere, causing damage to their electronics, memory and imaging systems. </p>
<p>For us on Earth, all this solar activity could bring with it beautiful <a href="https://theconversation.com/the-southern-lights-put-on-a-display-in-the-night-sky-28612">aurora</a> generated by geomagnetic storm activity. </p>
<p>The CME released by Tuesday’s flare was not directed right at Earth, so only a fraction of it will reach us. But even so, there’s predicted to be a high chance of aurora over the Earth’s polar regions in the next 24 hours or so.</p>
<p>But with today’s flare and CME pointed right at Earth, the aurora activity could be even more wide-spread and be seen down to lower altitudes. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58736/original/vjb3jzbh-1410399030.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&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 magnificent aurora over North America captured on August 20 by astronaut Reid Wiseman onboard the International Space Station.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>Geomagnetic storms can also disrupt communications with GPS and have been known to cause power outages. However, today’s solar activity is no where near as strong as the infamous flare that caused a <a href="http://www.nasa.gov/topics/earth/features/sun_darkness.html">widespread blackout</a> across Quebec, Canada, 25 years ago. </p>
<p>In fact, the sun has been showing unusual <a href="https://theconversation.com/why-is-the-sun-going-quiet-22155">low activity</a> in the past year of so, considering that the peak of the sun’s 11-year cycle was supposed to have occurred in 2013. </p>
<p>Instead the sun has been very quiet and even last July, there was almost a week where the <a href="http://spaceweather.com/archive.php?view=1&day=20&month=07&year=2014">sun had no sunspots</a>. So it’s exciting to see things heating up.</p><img src="https://counter.theconversation.com/content/31560/count.gif" alt="The Conversation" width="1" height="1" />
During the early hours of this morning (3:42am AEST) our sun released a strong solar flare. It follows right on the heels of a more moderate flare that was released from the same region of the sun on Tuesday…Tanya Hill, Honorary Fellow of the University of Melbourne and Senior Curator (Astronomy), Museums Victoria Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/287752014-07-14T04:24:30Z2014-07-14T04:24:30ZAre you a frequent flyer? Solar storm radiation can be harmful<figure><img src="https://images.theconversation.com/files/53494/original/t2qhmks7-1404963201.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Like Icarus, passengers on aircraft during solar flares can cop the effects of flying close to the sun.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/picturesfromcolin/5057397466">HK.Colin/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Space weather <a href="https://theconversation.com/solar-eruption-could-help-earth-prepare-for-technology-melt-down-18747">impacts</a> many modern-day technologies. But one of the most concerning – and least reported – space weather effects is the increased radiation exposure to passengers on commercial long-distance flights during so-called “<a href="http://www.spaceweather.com/glossary/srs.html">solar radiation storms</a>”. </p>
<p>The NASA-funded Nowcast of Atmospheric Ionizing Radiation System (<a href="http://sol.spacenvironment.net/%7Enairas/">NAIRAS</a>) is the computer system tasked with providing a real-time data-driven climatology of the aviation radiation environment.</p>
<p>Recently, a series of papers published in the journal [Space Weather](http://onlinelibrary.wiley.com/journal/10.1002/(ISSN%291542-7390) estimate that when NAIRAS was turned off during the US government shutdown last year – which went into effect just as a solar radiation storm began – <a href="http://onlinelibrary.wiley.com/doi/10.1002/2013SW001015/abstract">500,000 people</a> received increased radiation doses.</p>
<p>It has also been estimated that this event is likely to eventually result in four cancer-related deaths.</p>
<h2>What is a solar radiation storm?</h2>
<p>Disturbances on the surface of the sun are commonly the cause of geomagnetic disturbances here on Earth; such as power grid faults/failures and increased errors in GPS navigation and positioning. </p>
<p>Associated with some of these solar disturbances is the ejection of extremely fast plasma into the solar wind that, when aimed directly towards the Earth, causes the onset of increased geomagnetic and ionospheric activity. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/EEFQHDSYP1I?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The Earth-bound solar energetic particles ejected into the solar wind eventually penetrate into the Earth’s magnetosphere. </p>
<p>When inside the magnetosphere, they orbit the planet across the Earth’s magnetic field lines until they are scattered by various complicated magnetospheric processes and interactions. </p>
<p>Once scattered, these solar particles then travel down the magnetic field lines until they impact the Earth’s upper atmosphere, where they are effectively absorbed.</p>
<p>The penetration depth of these particles primarily depends on their kinetic energy, which is governed by their mass and velocity. </p>
<p>The less energetic particles are stopped by the Earth’s atmosphere typically between 100 and 400km altitude, causing the well-known <a href="http://spaceweathergallery.com/aurora_gallery.html">aurora</a> in the northern and southern high-latitude regions. </p>
<p>The atmosphere increases in density exponentially as the particle falls. This normally prevents particles penetrating to lower altitudes where they are harmful to living organisms. </p>
<p>The more energetic particles, called “solar energetic particles”, caused by these solar disturbances can <a href="http://www.dartmouth.edu/%7Ebarrel/index.html">penetrate</a> to below 10km, near the [cruising altitudes](http://en.wikipedia.org/wiki/Cruise_(aeronautics%29) of commercial flights.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/UHYbnv6O1Go?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>During such events, the danger posed by the increased radiation levels is easily averted by decreasing the cruising altitudes of the aircraft. Pilots can also divert their flight paths to areas less affected by the increased radiation levels (more equatorward latitudes). </p>
<h2>Several chest X-rays worth of radiation</h2>
<p>The aviation radiation monitoring performed in real-time by computer systems such as NAIRAS can effectively be used to issue such warnings to aircraft. </p>
<p>This will help remove the threat posed to hundreds of thousands of people across the globe during such space weather events.</p>
<p>The geomagnetic activity levels associated with the solar radiation storm that occurred during the US government shutdown were only minor (a minimum <a href="https://theconversation.com/solar-eruption-could-help-earth-prepare-for-technology-melt-down-18747">Dst</a> of -54nT).</p>
<p>This means the technologies normally classified as being <a href="https://theconversation.com/divert-power-to-shields-the-solar-maximum-is-coming-11228">vulnerable</a> to extreme space weather events are not likely to have been significantly affected. </p>
<p>The solar energetic particle levels observed by <a href="http://www.ngdc.noaa.gov/stp/satellite/goes/index.html">geostationary satellites</a> classifies this as an <a href="http://www.spaceweather.com/glossary/srs.html">S2</a> solar radiation storm. It lasted more than 24 hours, and took about four days to fully subside (see video below).</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Qurh_BZ-O2E?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Some controversy exists around the exact method used by the scientists of the first <a href="http://onlinelibrary.wiley.com/doi/10.1002/2013SW001015/abstract">study</a> into this event. There has been doubt around the estimation of the number of eventual cancer fatalities related to this solar radiation storm. </p>
<p>Even though the radiation levels air travellers were exposed to during this event are much higher than they might have been had an appropriate warning been issued, they were still comparatively low – on par with the dose that one would receive from a number of chest X-rays.</p>
<p>Arguments put forward by some <a href="http://onlinelibrary.wiley.com/doi/10.1002/2014SW001074/abstract">researchers</a> err on the side of caution. They indicate that some people who would be considered more vulnerable to increased radiation exposure (such as frequent flyers and unborn children) should have access to this radiation monitoring information. </p>
<p>This would enable them to make educated decisions about appropriate air travel times in much the same way that non-urgent X-rays may be postponed during pregnancy. </p>
<p><a href="http://onlinelibrary.wiley.com/doi/10.1002/2014SW001061/abstract">Other researchers</a> have erred on the opposite side, with the view that the radiation doses during this event were too small to be considered a serious threat.</p>
<p>Independent of whether or not this particular space weather event exposed air travellers to dangerous levels of radiation, these studies are in clear agreement that increasing radiation monitoring is a must in the future.</p>
<p>This is especially important for the aviation industry, and the provision of such information must not be hindered by short-term political partisan interests.</p><img src="https://counter.theconversation.com/content/28775/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Carter receives funding from the Victorian Postdoctoral Research Fellowship Program.</span></em></p>Space weather impacts many modern-day technologies. But one of the most concerning – and least reported – space weather effects is the increased radiation exposure to passengers on commercial long-distance…Brett Carter, Postdoctoral Researcher in Space Weather and Ionospheric Physics, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.