tag:theconversation.com,2011:/es/topics/mars-atmosphere-25755/articlesMars atmosphere – The Conversation2021-02-05T15:57:15Ztag:theconversation.com,2011:article/1544082021-02-05T15:57:15Z2021-02-05T15:57:15ZMars missions from China and UAE are set to go into orbit – here’s what they could discover<p>How times have changed since the Apollo era. Within the space of a few days, two space missions from China and the United Arab Emirates (UAE), respectively, are set to reach Mars. The <a href="https://www.emiratesmarsmission.ae">UAE’s Hope mission</a> will go into orbit around Mars on February 9. The next day, the <a href="https://www.nature.com/articles/s41550-020-1148-6">Chinese Tianwen-1 mission</a> – an orbiter and lander - will swing into orbit, with a predicted landing date sometime in May. </p>
<p>It is a very big moment for both countries. Hope is the first interplanetary mission by an Arab nation ever. And if China succeeds, it will be the first country ever to visit and land on Mars on its first try. The odds are stacked against them with <a href="https://www.space.com/32199-mars-missions-history-successes-failures.html">nearly 50% of all Mars missions failing</a>. China already <a href="https://www.bbc.co.uk/news/science-environment-16491457">lost a Mars orbiter mission (Yinghuo-1)</a> back in 2011.</p>
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<p><em>For more on the upcoming Mars missions, listen to the first episode of our new podcast, <a href="https://theconversation.com/uk/topics/the-conversation-weekly-98901">The Conversation Weekly</a> – the world explained by experts. Subscribe wherever you get your podcasts.</em> </p>
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<p>But before the missions can start doing science, tense moments await. As they arrive at the planet, they need to trigger a burn of their engines just at the right time to slow the probes down so they can be captured by Mars’ gravitational field. Given the large distance from Earth, this needs to be carried out automatically by the probe. </p>
<h2>Tianwen-1</h2>
<p>If all goes well, the orbiter Tianwen, which means <a href="https://www.nature.com/articles/s41550-020-1148-6">“Questions to Heaven”</a> and the yet unnamed rover will attempt to measure Mars’s climate and “<a href="https://solarsystem.nasa.gov/news/1127/10-things-to-know-about-the-ionosphere/">ionosphere</a>”, a layer of electrically charged particles surrounding the planet. This work might help to understand <a href="https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space">how Mars is losing its atmosphere</a>. But it will also support future crewed missions to Mars by exploring its surface <a href="http://www.cjss.ac.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=2602">and mapping</a> its shape, geology and internal structure. </p>
<p>The orbiter is packed with cameras, a magnetometer (used to measure magnetic fields) and various particle analysers. It will also act as a relay station to stay in communication with the rover. The rover, the size of a small car, is just a little bit smaller than the <a href="https://mars.nasa.gov/mars2020/">NASA Perseverance rover</a>, which is also approaching Mars. It flouts a similar look, with a six-wheel drive, large solar panels and a pole with cameras attached. The latter will be able to identify surface compositions at a distance of between two metres and five metres.</p>
<p>What makes this mission even more fascinating is that the rover contains a ground-penetrating radar. During the rover’s estimated lifespan of 90 Martian days - a Martian day being nearly 38 minutes longer than ours - it can explore the sub-surface structure and search for water deposits below the ground. Evidence of underground saltwater lakes <a href="https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Mars_Express_detects_liquid_water_hidden_under_planet_s_south_pole">was found</a> using radar in 2018 by the <a href="https://sci.esa.int/web/mars-express">European Mars Express Orbiter</a>, but never followed up with measurements from the surface. </p>
<p>The rover will not visit these specific sites but could find similar conditions at the proposed landing site, which we know used to be covered by mudflats. There’s huge interest in such deposits as they represent a resource for future astronauts on the planet. We also can’t rule out the possibility that the lakes <a href="https://theconversation.com/mars-mounting-evidence-for-subglacial-lakes-but-could-they-really-host-life-146732">could host some form of life</a>.</p>
<p>China has already used the radar technology with great success on its recent Yutu-2 rover to identify <a href="https://skyandtelescope.org/astronomy-news/what-lies-beneath-moon-farside/">separate unique layers of water ice</a> up to 40m below the surface on the Moon. </p>
<p>The Chinese National Space Administration stated that <a href="https://www.space.com/china-mars-rover-tianwen-1-landing-site">the rover will land</a> in the region known as Utopia Planitia, the largest known impact basin in the solar system. In the first three months, the orbiter will survey and identify the precise location.</p>
<p>Curiously, a press release from after the successful launch of the mission initially indicated the <a href="http://www.spaceflightfans.cn/77341.html">intended coordinates within Utopia Planitia</a> (110.318 degrees east longitude and 24.748 degrees north latitude), but these were swiftly removed, possibly to ensure this does not contradict a later slight alteration – or with political motivatation. <a href="https://www.space.com/china-mars-rover-tianwen-1-landing-site">Speaking to Space.com</a>, <a href="https://www.lpl.arizona.edu/faculty/mcewen">Alfred McEwen</a>, director of the Planetary Image Research Laboratory at the University of Arizona, said the intended landing area is safe and scientifically very interesting. </p>
<p>China’s first Mars rover will need to go through the so-called <a href="https://www.jpl.nasa.gov/videos/curiositys-seven-minutes-of-terror/">seven minutes of terror</a>: the automated decent of any lander through the Martian atmosphere to successfully decelerate and land in one piece, all without any active communication with an orbiter or ground control. To achieve this, it will do an initial deceleration using a “conical aeroshell”, which is a protective shield that causes aerodynamic drag (resistance) but will heat up immensely, followed by a parachute and then the firing of retrorockets to the allow a soft touch down. </p>
<h2>Hopeful UAE</h2>
<p>The Hope mission is the UAE’s first ever interplanetary mission arriving at Mars at the same time as the UAE is <a href="https://www.bbc.co.uk/news/science-environment-53394737">celebrating its 50th anniversary of formation</a>. This mission blasted off from Japan in July 2020 using the same “launch window” (the best time for a probe to set off and easily reach Mars from Earth) to reach Mars as the Chinese and Nasa missions. </p>
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<p>Hope is set to orbit Mars for one Martian year – nearly two Earth years. From distances between 22,000km up to 44,000km, it will explore in more detail the martian atmosphere. The <a href="https://www.emiratesmarsmission.ae/">mission will investigate</a> the global weather, its links to the upper atmosphere and how this can explain the changing abundance of hydrogen and oxygen there. This will help us understand how Mars is gradually losing its atmosphere and the role that dust plays in the Martian weather – also important information for those who want to settle on Mars one day.</p>
<p>These busy times for all interested in Mars exploration have been kicked off by two relative newcomers in the treacherous business of Martian exploration, bringing a welcome, fresh perspective. It’s brilliant to see the group of nations exploring Mars expanding. And if you haven’t had enough seeing these missions arriving, then sit back for a few days until February 18, when NASA’s Perseverance rover will join them.</p><img src="https://counter.theconversation.com/content/154408/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 China succeeds, it will be the first country ever to visit and land on Mars on its first try.Daniel Brown, Lecturer in Astronomy, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1228572019-09-05T05:01:59Z2019-09-05T05:01:59ZTiny specks in space could be the key to finding martian life<figure><img src="https://images.theconversation.com/files/291046/original/file-20190905-175705-19z1try.jpg?ixlib=rb-1.1.0&rect=30%2C17%2C2845%2C1780&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Much of Mars's surface is covered by fine-grained materials that hide the bedrock. The above bedrock is mostly exposed and it is in these areas that micrometeorites likely to accumulate.</span> <span class="attribution"><span class="source">NASA/JPL-Caltech/Univ. of Arizona</span></span></figcaption></figure><p>Next year, both NASA and the European Space Agency (ESA) will send new rovers to Mars to hunt for evidence of past life.</p>
<p>As previous missions have discovered, Mars had a <a href="https://doi.org/10.1146/annurev-earth-060115-012355">warmer and wetter past</a>, featuring conditions that could probably sustain life. Current satellites orbiting Mars also reveal there are many places where water was once present on the surface. </p>
<p>The difficulty in hunting for life lies not in finding where there was water, but in identifying where the essential nutrients for life coincided with water. </p>
<h2>Micrometeorites mean potential life</h2>
<p>For life to move into a new environment and survive, it needs essential nutrients such as carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (together known as <a href="https://en.wikipedia.org/wiki/CHON">CHNOPS</a>), plus other trace elements. It also needs to acquire energy from the environment. Some of Earth’s earliest life forms gained energy by oxidising minerals.</p>
<p>Mars’s crust is mostly made of intrusive and volcanic basalt (the same rock that forms from Hawaii’s lavas) which is not particularly nutrient-rich. However, meteorites and micrometeorites are known to continuously provide essential nutrients to the surfaces of planets. </p>
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Read more:
<a href="https://theconversation.com/hope-springs-signs-of-life-could-be-waiting-for-us-on-mars-11800">Hope springs: signs of life could be waiting for us on Mars</a>
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<p><a href="https://doi.org/10.1029/2019JE006005">Our team investigated</a> how much cosmic dust (comet and asteroid dust) would survive atmospheric entry to Mars, and where it would accumulate on the surface as micrometeorites.</p>
<p>We <a href="https://doi.org/10.1111/maps.13360">modelled the heating and oxidation</a> effects of atmospheric entry to Mars and found most particles less than about 0.1-0.2mm in diameter would not melt, depending on their composition. In terms of materials accumulating on the martian surface, particles of this size are overwhelmingly more common than larger particles.</p>
<p>On Earth, about 100 times as much cosmic dust in this size range accumulates on the surface, when compared to meteorites larger than 4mm. This is despite extensive melting and evaporation during atmospheric entry to Earth. </p>
<h2>Evidence closer to home</h2>
<p>As part of our research, we used an analogue site on the Nullarbor Plain in South Australia (which, like Mars, has wind-modified sediment sitting on cracked bedrock) to examine whether wind causes micrometeorites to accumulate at predictable locations. </p>
<p>We found more than 1,600 micrometeorites from a variety of sample sites.</p>
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<img alt="" src="https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=471&fit=crop&dpr=1 600w, https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=471&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=471&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/291022/original/file-20190904-175682-fzkd33.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">
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<span class="caption">Microscope image of a sectioned micrometeorite from the Nullarbor Plain, Australia. The bright sphere is iron-nickel metal, the grey minerals are iron oxides.</span>
<span class="attribution"><span class="source">Angus Rogers</span></span>
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<p>Our observations show that because many micrometeorites are denser than normal sand grains, they are likely to accumulate in bedrock cracks and on gravel-rich surfaces where lighter particles have been blown away. Our samples typically contained several hundred micrometeorites per kilogram. </p>
<p>Several factors added together indicate that micrometeorites should be much more abundant on Mars than on Earth. And this is expected to be true for most of Mars’s 4.5-billion-year history. </p>
<h2>Even martians need nutrients</h2>
<p>Unmelted and partially melted micrometeorites supply complex carbon compounds to the martian surface, which are the building blocks of life. They also supply the only source of reduced phosphorus through the mineral <a href="https://www.mindat.org/min-3582.html">schreibersite</a>, which has been shown to react with simple hydroxyl compounds to <a href="https://www.nature.com/articles/srep17198">form the precursors for life</a>. </p>
<p>Micrometeorites also provide other reduced minerals like sulfides and iron-nickel metal that can be exploited as an energy source by primitive microbes. Therefore, they provide both the essential nutrients and an energy source that can allow existing microbes to migrate and persist. </p>
<h2>Mars 2020</h2>
<p>Many scientists believe life on Earth may have started around <a href="https://en.wikipedia.org/wiki/Hydrothermal_vent">undersea geothermal vents</a> or in volcanic hot springs like those at <a href="https://en.wikipedia.org/wiki/Geothermal_areas_of_Yellowstone">Yellowstone</a> or <a href="https://en.wikipedia.org/wiki/Waiotapu">Rotorua</a>. Beneath these, water circulates through the hot crust, dissolving nutrients from the rocks and carrying them upwards to the vents, where there are dramatic changes in temperature and chemistry. </p>
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Read more:
<a href="https://theconversation.com/evidence-of-ancient-life-in-hot-springs-on-earth-could-point-to-fossil-life-on-mars-77388">Evidence of ancient life in hot springs on Earth could point to fossil life on Mars</a>
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<p>This creates a large range of niche environments, some of which have the ideal combination of water, temperate conditions and chemistry for life.</p>
<p>The expired Spirit rover found evidence of an <a href="https://www.nasa.gov/mission_pages/mer/mer-20070521.html">extinct volcanic spring on Mars</a> and more have been inferred from orbital observations. These volcanic springs were considered as a landing site for NASA’s Mars 2020 rover, but in the end Jezero Crater was chosen.</p>
<p>Jezero Crater has a combination of water-produced channels in a delta system that contains clay and carbonate minerals <a href="https://www.nature.com/articles/ngeo207">in sedimentary rocks</a>. These are ideal for <a href="https://www.nature.com/articles/srep05841">preserving</a> <a href="https://science.sciencemag.org/content/295/5555/657">geochemical signs</a> of life. Similarly, Oxia Planum has been chosen as the landing site for ESA’s ExoMars rover, which also contains clays in sedimentary deposits. </p>
<p>While neither Jezero Crater or Oxia Planum contain known volcanic springs, they are still water-rich environments where life may have existed on Mars. </p>
<p>Micrometeorites provide the nutrients that may have allowed life to migrate into and persist at these locations, and could even provide the ingredients for life to emerge away from Mars’s volcanic springs.</p>
<p>With plans in the works for 2020, we may soon be on the cusp of one of the greatest scientific breakthroughs of all time.</p><img src="https://counter.theconversation.com/content/122857/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Tomkins receives funding from the Australian Research Council. </span></em></p>It’s established Mars was once a planet with surface-level water. So with multiple MARS missions starting next year, the key to seeking out martian life may instead lie in the contents of its ‘dust’.Andrew Tomkins, Geologist, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1030532018-11-06T11:41:10Z2018-11-06T11:41:10ZColonizing Mars means contaminating Mars – and never knowing for sure if it had its own native life<figure><img src="https://images.theconversation.com/files/242763/original/file-20181029-76411-ioau9b.jpg?ixlib=rb-1.1.0&rect=814%2C0%2C3775%2C2574&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Once people get there, Mars will be contaminated with Earth life.</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/multimedia/imagegallery/image_feature_261.html">NASA/Pat Rawlings, SAIC</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The closest place in the universe where extraterrestrial life might exist is Mars, and human beings are poised to attempt to colonize this planetary neighbor within the next decade. Before that happens, we need to recognize that a very real possibility exists that the first human steps on the Martian surface will lead to a collision between terrestrial life and biota native to Mars.</p>
<p>If the red planet is sterile, a human presence there would create no moral or ethical dilemmas on this front. But if life does exist on Mars, human explorers could easily lead to the extinction of Martian life. <a href="https://scholar.google.com/citations?user=KOrEwdkAAAAJ&hl=en&oi=ao">As an astronomer</a> who explores these questions in my book “<a href="https://press.princeton.edu/titles/11233.html">Life on Mars: What to Know Before We Go</a>,” I contend that we Earthlings need to understand this scenario and debate the possible outcomes of colonizing our neighboring planet in advance. Maybe missions that would carry humans to Mars need a timeout.</p>
<h2>Where life could be</h2>
<p>Life, scientists suggest, has some basic requirements. It could exist anywhere in the universe that has liquid water, a source of heat and energy, and copious amounts of a few essential elements, such as carbon, hydrogen, oxygen, nitrogen and potassium.</p>
<p>Mars qualifies, as do at least two other places in our solar system. Both <a href="https://solarsystem.nasa.gov/moons/jupiter-moons/europa/in-depth/">Europa</a>, one of Jupiter’s large moons, and <a href="https://solarsystem.nasa.gov/moons/saturn-moons/enceladus/in-depth/">Enceladus</a>, one of Saturn’s large moons, appear to possess these prerequisites for hosting native biology.</p>
<p>I suggest that how scientists planned the exploratory missions to these two moons provides valuable background when considering how to explore Mars without risk of contamination.</p>
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<a href="https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=685&fit=crop&dpr=1 600w, https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=685&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=685&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=860&fit=crop&dpr=1 754w, https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=860&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/242558/original/file-20181026-7050-3k87rh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=860&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Cassini shot this false-color image of jets erupting from the southern hemisphere of Enceladus on Nov. 27, 2005.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/mission_pages/cassini/media/saturn_sponge.html">NASA/JPL/Space Science Institute</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Below their thick layers of surface ice, both Europa and Enceladus have global oceans in which 4.5 billion years of churning of the primordial soup may have enabled life to develop and take root. NASA spacecraft have even imaged spectacular geysers ejecting plumes of water out into space from these subsurface oceans.</p>
<p>To find out if either moon has life, planetary scientists are actively developing the <a href="https://europa.nasa.gov/">Europa Clipper mission</a> for a 2020s launch. They also hope to plan future missions that will target Enceladus.</p>
<h2>Taking care to not contaminate</h2>
<p>Since the start of the space age, scientists have taken the threat of biological contamination of other worlds seriously. As early as 1959, NASA held meetings <a href="https://www.nasa.gov/connect/ebooks/when_biospheres_collide_detail.html">to debate the necessity of sterilizing spacecraft</a> that might be sent to other worlds. Since then, all planetary exploration missions have adhered to sterilization standards that balance their scientific goals with limitations of not damaging sensitive equipment, which could potentially lead to mission failures. Today, NASA protocols exist for the <a href="https://sma.nasa.gov/sma-disciplines/planetary-protection">protection of all solar system bodies</a>, including Mars.</p>
<p>Since avoiding the biological contamination of Europa and Enceladus is an extremely well-understood, high-priority requirement of all missions to the Jovian and Saturnian environments, their moons remain uncontaminated.</p>
<p>NASA’s <a href="https://solarsystem.nasa.gov/missions/galileo/overview/">Galileo mission explored Jupiter</a> and its moons from 1995 until 2003. Given Galileo’s orbit, the possibility existed that the spacecraft, once out of rocket propellant and subject to the whims of gravitational tugs from Jupiter and its many moons, could someday crash into and thereby contaminate Europa. </p>
<p>Such a collision might not occur until many millions of years from now. Nevertheless, though the risk was small, it was also real. NASA paid close attention to guidance from the <a href="https://www.nap.edu/initiative/committee-on-planetary-and-lunar-exploration">National Academies’ Committee on Planetary and Lunar Exploration</a>, which noted serious national and international objections to the possible accidental disposal of the Galileo spacecraft on Europa.</p>
<p>To completely eliminate any such risk, on Sept. 21, 2003, NASA used the last bit of fuel on the spacecraft to send it plunging into Jupiter’s atmosphere. At a speed of 30 miles per second, <a href="https://www.nasa.gov/vision/universe/solarsystem/galileo_final.html">Galileo vaporized within seconds</a>.</p>
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<figcaption><span class="caption">Cassini’s ‘Grand Finale’ ended with the spacecraft burning up in Saturn’s atmosphere.</span></figcaption>
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<p>Fourteen years later, NASA repeated this protect-the-moon scenario. The <a href="https://solarsystem.nasa.gov/missions/cassini/overview/">Cassini mission orbited and studied Saturn</a> and its moons from 2004 until 2017. On Sept. 15, 2017, when fuel had run low, on instructions from NASA Cassini’s operators deliberately <a href="https://saturn.jpl.nasa.gov/mission/about-the-mission/summary/">plunged the spacecraft into Saturn’s atmosphere</a>, where it disintegrated.</p>
<h2>But what about Mars?</h2>
<p>Mars is the target of <a href="https://mars.nasa.gov/#missions">seven active missions</a>, including two rovers, <a href="https://mars.nasa.gov/programmissions/missions/present/2003/">Opportunity</a> and <a href="https://mars.nasa.gov/msl/mission/mars-rover-curiosity-mission-updates/">Curiosity</a>. In addition, on Nov. 26 NASA’s <a href="https://mars.nasa.gov/insight/">InSight mission</a> is scheduled to land on Mars, where it will make measurements of Mars’ interior structure. Next, with planned 2020 launches, both ESA’s <a href="http://exploration.esa.int/mars/48088-mission-overview/">ExoMars rover</a> and NASA’s <a href="https://mars.nasa.gov/mars2020/">Mars 2020 rover</a> are designed to search for evidence of life on Mars.</p>
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<a href="https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=540&fit=crop&dpr=1 754w, https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=540&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/242772/original/file-20181029-76413-otea1r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=540&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Curiosity rover was tested under clean conditions on Earth before launch to prevent microbial stowaways.</span>
<span class="attribution"><a class="source" href="https://www.nasa.gov/mission_pages/msl/msl20100913.html">NASA/JPL-Caltech</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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</figure>
<p>The good news is that robotic rovers pose little risk of contamination to Mars, since all spacecraft designed to land on Mars are subject to <a href="https://www.nasa.gov/missions/solarsystem/mer_clean.html">strict sterilization procedures before launch</a>. This has been the case since NASA imposed “rigorous sterilization procedures” for the <a href="https://mars.nasa.gov/programmissions/missions/past/viking/">Viking Lander Capsules</a> in the 1970s, since they would directly contact the Martian surface. These rovers likely have an extremely low number of microbial stowaways.</p>
<p>Any terrestrial biota that do manage to hitch rides on the outside of those rovers would have a very hard time surviving the half-year journey from Earth to Mars. The vacuum of space combined with exposure to harsh X-rays, ultraviolet light and cosmic rays would <a href="https://www.nasa.gov/connect/ebooks/when_biospheres_collide_detail.html">almost certainly sterilize the outsides of any spacecraft</a> sent to Mars.</p>
<p>Any bacteria that sneaked rides inside one of the rovers might arrive at Mars alive. But if any escaped, the <a href="https://www.space.com/16903-mars-atmosphere-climate-weather.html">thin Martian atmosphere</a> would offer virtually no protection from high energy, sterilizing radiation from space. Those bacteria would likely be killed immediately. Because of this harsh environment, life on Mars, if it currently exists, almost certainly must be hiding beneath the planet’s surface. Since no rovers have explored caves or dug deep holes, we have not yet had the opportunity to come face-to-drill-bit with any possible Martian microbes.</p>
<p>Given that the exploration of Mars has so far been limited to unmanned vehicles, the planet likely remains free from terrestrial contamination.</p>
<p>But when Earth sends astronauts to Mars, they’ll travel with life support and energy supply systems, habitats, 3D printers, food and tools. None of these materials can be sterilized in the same ways systems associated with robotic spacecraft can. Human colonists will produce waste, try to grow food and use machines to extract water from the ground and atmosphere. Simply by living on Mars, human colonists will contaminate Mars.</p>
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<h2>Can’t turn back the clock after contamination</h2>
<p>Space researchers have developed a careful approach to robotic exploration of Mars and a hands-off attitude toward Europa and Enceladus. Why, then, are we collectively willing to overlook the risk to Martian life of human exploration and colonization of the red planet?</p>
<p>Contaminating Mars isn’t an unforeseen consequence. A quarter century ago, a National Research Council report entitled <a href="https://doi.org/10.17226/12305">“Biological Contamination of Mars: Issues and Recommendations”</a> asserted that missions carrying humans to Mars will inevitably contaminate the planet. </p>
<p>I believe it’s critical that every attempt be made to obtain evidence of any past or present life on Mars well in advance of future missions to Mars that include humans. What we discover could influence our collective decision whether to send colonists there at all.</p>
<p>Even if we ignore or don’t care about the risks a human presence would pose to Martian life, the issue of bringing Martian life back to Earth has serious societal, legal and international implications that deserve discussion before it’s too late. What risks might Martian life pose to our environment or our health? And does any one country or group have the right to risk back contamination if those Martian lifeforms could attack the DNA molecule and thereby put all of life on Earth at risk?</p>
<p>But players both public – NASA, United Arab Emirates’ <a href="https://government.ae/en/more/uae-future/2030-2117">Mars 2117 project</a> – and private – <a href="https://www.spacex.com/mars">SpaceX</a>, <a href="https://www.mars-one.com">Mars One</a>, <a href="https://www.blueorigin.com">Blue Origin</a> – already plan to transport colonists to build cities on Mars. And these missions will contaminate Mars. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=312&fit=crop&dpr=1 600w, https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=312&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=312&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=392&fit=crop&dpr=1 754w, https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=392&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/242775/original/file-20181029-76399-1ozr59w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=392&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Scientists hypothesize that dark narrow streaks were formed by briny liquid water – necessary for life – flowing down the walls of a crater on Mars.</span>
<span class="attribution"><a class="source" href="https://mars.nasa.gov/resources/7488/dark-recurring-streaks-on-walls-of-garni-crater/">NASA/JPL-Caltech/Univ. of Arizona</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p><a href="https://doi.org/10.1126/science.1165243">Some scientists believe they</a> <a href="https://doi.org/10.1126/science.aaq0131">have already uncovered</a> <a href="https://www.nasa.gov/press-release/nasa-finds-ancient-organic-material-mysterious-methane-on-mars">strong evidence for life on Mars</a>, both past and present. If life already exists on Mars, then Mars, for now at least, belongs to the Martians. Mars is their planet, and Martian life would be threatened by a human presence there.</p>
<p>Does humanity have an inalienable right to colonize Mars simply because we will soon be able to do so? We have the technology to use robots to determine whether Mars is inhabited. Do ethics demand that we use those tools to answer definitively whether Mars is inhabited or sterile before we put human footprints on the Martian surface?</p><img src="https://counter.theconversation.com/content/103053/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Weintraub 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>NASA’s InSight Mars lander touches down Nov. 26, part of a careful robotic approach to exploring the red planet. But human exploration of Mars will inevitably introduce Earth life. Are you OK with that?David Weintraub, Professor of Astronomy, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/999432018-07-26T05:39:42Z2018-07-26T05:39:42ZHow to grow crops on Mars if we are to live on the red planet<figure><img src="https://images.theconversation.com/files/229365/original/file-20180726-106502-1nt78ux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We can create the right kind of food plants to survive on Mars.</span> <span class="attribution"><span class="source">Shutterstock/SergeyDV</span></span></figcaption></figure><p>Preparations are <a href="https://www.nasa.gov/content/journey-to-mars-overview">already underway</a> for <a href="https://theconversation.com/the-new-space-race-why-we-need-a-human-mission-to-mars-73757">missions</a> that will land humans on Mars in a decade or so. But what would people eat if these missions eventually lead to the permanent colonisation of the red planet?</p>
<p>Once (if) humans do make it to Mars, a major challenge for any colony will be to generate a stable supply of food. The enormous costs of launching and resupplying resources from Earth will make that impractical.</p>
<p>Humans on Mars will need to move away from complete reliance on shipped cargo, and achieve a high level of self-sufficient and sustainable agriculture.</p>
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Read more:
<a href="https://theconversation.com/discovered-a-huge-liquid-water-lake-beneath-the-southern-pole-of-mars-100523">Discovered: a huge liquid water lake beneath the southern pole of Mars</a>
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<p>The <a href="http://science.sciencemag.org/content/early/2018/07/24/science.aar7268">recent discovery</a> of liquid water on Mars – which adds new information to the question of whether we will find life on the planet – does raise the possibility of using such supplies to help grow food.</p>
<p>But water is only one of many things we will need if we’re to grow enough food on Mars.</p>
<h2>What sort of food?</h2>
<p>Previous work has suggested the use of <a href="http://rsif.royalsocietypublishing.org/content/12/102/20140715">microbes</a> as a source of food on Mars. The use of <a href="https://www.nasa.gov/feature/lunar-martian-greenhouses-designed-to-mimic-those-on-earth">hydroponic greenhouses</a> and controlled environmental systems, similar to <a href="https://www.nasa.gov/mission_pages/station/research/10-074.html">one being tested</a> onboard the International Space Station to grow crops, is another option.</p>
<p><a href="https://doi.org/10.3390/genes9070348">This month</a>, in the journal Genes, we provide a new perspective based on the use of advanced synthetic biology to improve the potential performance of plant life on Mars.</p>
<p>Synthetic biology is a fast-growing field. It combines principles from engineering, DNA science, and computer science (among many other disciplines) to impart new and improved functions to living organisms.</p>
<p>Not only can we read DNA, but we can also design biological systems, test them, and even engineer whole organisms. <a href="http://syntheticyeast.org/sc2-0/introduction/">Yeast</a> is just one example of an industrial workhorse microbe whose whole genome is currently being re-engineered by an international consortium.</p>
<p>The technology has progressed so far that precision genetic engineering and automation can now be merged into automated robotic facilities, known as biofoundries.</p>
<p>These biofoundries can test millions of DNA designs in parallel to find the organisms with the qualities that we are looking for.</p>
<h2>Mars: Earth-like but not Earth</h2>
<p>Although Mars is the most Earth-like of our neighbouring planets, Mars and Earth differ in many ways.</p>
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<strong>
Read more:
<a href="https://theconversation.com/dear-diary-the-sun-never-set-on-the-arctic-mars-simulation-84597">Dear diary: the Sun never set on the Arctic Mars simulation</a>
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<p>The gravity on Mars is around a third of that on Earth. Mars receives about half of the sunlight we get on Earth, but much higher levels of harmful ultraviolet (UV) and cosmic rays. The surface temperature of Mars is about -60°C and it has a thin atmosphere primarily made of carbon dioxide.</p>
<p>Unlike Earth’s soil, which is humid and rich in nutrients and microorganisms that support plant growth, Mars is covered with <a href="https://www.britannica.com/science/regolith">regolith</a>. This is an arid material that contains <a href="https://www.space.com/37402-mars-life-soil-toxic-perchlorates-radiation.html">perchlorate chemicals</a> that are toxic to humans.</p>
<p>Also – despite the latest sub-surface lake find – water on Mars mostly exists in the form of ice, and the low atmospheric pressure of the planet makes liquid water boil at around 5°C.</p>
<p>Plants on Earth have evolved for hundreds of millions of years and are adapted to terrestrial conditions, but they will not grow well on Mars. </p>
<p>This means that substantial resources that would be scarce and priceless for humans on Mars, like liquid water and energy, would need to be allocated to achieve efficient farming by artificially creating optimal plant growth conditions.</p>
<h2>Adapting plants to Mars</h2>
<p>A more rational alternative is to use synthetic biology to develop crops specifically for Mars. This formidable challenge can be tackled and fast-tracked by building a plant-focused Mars biofoundry. </p>
<p>Such an automated facility would be capable of expediting the engineering of biological designs and testing of their performance under simulated Martian conditions.</p>
<p>With adequate funding and active international collaboration, such an advanced facility could improve many of the traits required for making crops thrive on Mars within a decade. </p>
<p>This includes improving <a href="https://www.britannica.com/science/photosynthesis">photosynthesis</a> and photoprotection (to help protect plants from sunlight and UV rays), as well as drought and cold tolerance in plants, and engineering high-yield functional crops. We also need to modify microbes to detoxify and improve the Martian soil quality.</p>
<p>These are all challenges that are within the capability of modern synthetic biology.</p>
<h2>Benefits for Earth</h2>
<p>Developing the next generation of crops required for sustaining humans on Mars would also have great benefits for people on Earth.</p>
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Read more:
<a href="https://theconversation.com/before-we-colonise-mars-lets-look-to-our-problems-on-earth-87770">Before we colonise Mars, let's look to our problems on Earth</a>
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<p>The growing global population is <a href="https://theconversation.com/the-future-of-food-growing-more-with-the-same-land-35559">increasing the demand for food</a>. To meet this demand we must increase agricultural productivity, but we have to do so without negatively impacting our environment.</p>
<p>The best way to achieve these goals would be to improve the crops that are already widely used. Setting up facilities such as the proposed Mars Biofoundry would bring immense benefit to the turnaround time of plant research with implications for food security and environmental protection.</p>
<p>So ultimately, the main beneficiary of efforts to develop crops for Mars would be Earth.</p><img src="https://counter.theconversation.com/content/99943/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Briardo Llorente receives funding from the CSIRO Synthetic Biology Future Science Platform and Macquarie University. </span></em></p>If humans are to live on Mars they will need a stable supply of food. Earth plants are not suited to the Mars climate but we can engineer plants that are.Briardo Llorente, CSIRO Synthetic Biology Future Science Fellow, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/877702017-12-27T20:46:49Z2017-12-27T20:46:49ZBefore we colonise Mars, let’s look to our problems on Earth<figure><img src="https://images.theconversation.com/files/199343/original/file-20171215-16456-1ar4m9m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mars NASA JPL Caltech cd f d o</span> </figcaption></figure><p>Everyone wants to go to Mars, or so it seems. </p>
<p>Elon Musk, NASA with Lockheed Martin, and now Boeing are all looking towards the red planet, with heady predictions of missions during the 2020s. </p>
<p>But at what cost? And could we even survive any long-term colonisation on Mars? Given the problems we face here on Earth it’s important to ask whether we should be better tasked with looking after the only planet we know (so far) that can harbour life.</p>
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Read more:
<a href="https://theconversation.com/revealed-today-elon-musks-new-space-vision-took-us-from-earth-to-mars-and-back-home-again-84837">Revealed today, Elon Musk's new space vision took us from Earth to Mars, and back home again</a>
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<h2>The race to Mars</h2>
<p>Boeing says it wants <a href="http://fortune.com/2017/12/07/boeing-dennis-muilenburg-elon-musk-mars/">to be involved in the first mission to send humans</a> to the red planet. The company’s chief executive Dennis Muilenburg told a US TV host in December 2017:</p>
<blockquote>
<p>I firmly believe the first person that sets foot on Mars will get there on a Boeing rocket. </p>
</blockquote>
<p>A key rival is Musk, the billionaire founder of SpaceX, which is already <a href="http://www.spacex.com/missions">launching rockets</a>. At the 68th Annual International Aeronautics Congress, in Adelaide in September 2017, Musk spoke of <a href="http://www.news.com.au/national/south-australia/elon-musk-to-detail-his-mission-to-mars-at-international-astronautical-congress-in-adelaide-on-friday/news-story/53708c3d16e4070a66aab3d0b8b7477a">airline-like connections</a> between Earth and Mars, with cargo missions to begin by 2022. </p>
<p>Lockheed Martin says it <a href="https://www.scientificamerican.com/article/lockheed-martin-reveals-plans-for-sending-humans-to-mars/">plans to send humans to Mars</a> in the next decade. </p>
<p>Even the famous theoretical physicist Stephen Hawking <a href="http://news.bbc.co.uk/today/hi/today/newsid_9672000/9672233.stm">has argued</a> that it is “essential that we colonise space” although he doesn’t see it happening that soon:</p>
<blockquote>
<p>I believe that we will eventually establish self-sustaining colonies on Mars and other bodies in the Solar system although probably not within the next 100 years.</p>
</blockquote>
<h2>Exploring other planets</h2>
<p>Scientific exploration of Solar system planets constitutes one of the most exciting achievements the human race is realising.</p>
<p>But by contrast, the idea of colonising Mars or other planets or moons is misleading. It yields an impression in many people’s mind that an alternative exists to Earth, a unique (so far) haven of life in the Solar system, currently suffering from <a href="https://theconversation.com/au/topics/global-warming-2768">global warming</a>, <a href="https://theconversation.com/contributions-to-sea-level-rise-have-increased-by-half-since-1993-largely-because-of-greenlands-ice-79175">rising oceans</a>, <a href="https://theconversation.com/not-just-heat-even-our-spring-frosts-can-bear-the-fingerprint-of-climate-change-89029">extreme weather events</a>, <a href="https://theconversation.com/earths-sixth-mass-extinction-has-begun-new-study-confirms-43432">mass extinction of species</a> and <a href="https://theconversation.com/why-we-signed-the-open-letter-from-scientists-supporting-a-total-ban-on-nuclear-weapons-75209">growing risk of nuclear wars</a>.</p>
<p>Microbial life <a href="https://www.smithsonianmag.com/science-nature/life-on-mars-78138144/">may exist on Mars</a> or <a href="https://www2.jpl.nasa.gov/snc/nasa1.html">may have existed in the past</a>. <a href="https://www.nasa.gov/mission_pages/mars/overview/index.html">According to NASA</a>:</p>
<blockquote>
<p>Among our discoveries about Mars, one stands out above all others: the possible presence of liquid water, either in its ancient past or preserved in the subsurface today. Water is key because almost everywhere we find water on Earth, we find life. If Mars once had liquid water, or still does today, it’s compelling to ask whether any microscopic life forms could have developed on its surface.</p>
</blockquote>
<p>But doubts have been raised recently with regard to the distinction between water and <a href="https://www.nasa.gov/feature/jpl/recurring-martian-streaks-flowing-sand-not-water">sand flow on Mars</a>.</p>
<h2>No atmosphere for life</h2>
<p>At present there is no evidence of a liveable atmosphere under which plants or other organisms would survive on Mars. </p>
<p>Its <a href="https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html">thin atmosphere</a> is less than 1% of Earth’s, consisting of 96% carbon dioxide, 1.9% nitrogen, 1.9% argon and trace amounts of oxygen and carbon monoxide. It provides little protection from the Sun’s radiation, nor does it allow retention of heat at the surface.</p>
<p>Suggestions as to whether <a href="https://www.space.com/33690-allen-hills-mars-meteorite-alien-life-20-years.html">biological-like textures</a> in a Martian meteorite (<a href="https://www.lpi.usra.edu/lpi/meteorites/The_Meteorite.shtml">ALH84001</a>) signify ancient fossils have not been confirmed.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=516&fit=crop&dpr=1 754w, https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=516&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/199135/original/file-20171214-27575-1xga58h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=516&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">This high-resolution scanning electron microscope image shows an unusual tube-like structural form that is less than 1/100th the width of a human hair in size found in meteorite ALH84001, a meteorite believed to be of Martian origin.</span>
<span class="attribution"><a class="source" href="https://spaceflight.nasa.gov/gallery/images/exploration/marsexploration/html/s96_12609.html">NASA</a></span>
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<p>In July 2017 <a href="https://www.nature.com/articles/s41598-017-04910-3">researchers reported</a> that the surface of Mars may be more toxic to microorganisms than previously thought.</p>
<h2>A Mars colony warning</h2>
<p>There is <a href="https://www.vox.com/science-and-health/2016/9/30/13099898/mars-death-risk-illustrated">no lack of warnings</a> regarding the colonisation of Mars.</p>
<p>If a colony was established it would take continuous efforts and major expense to keep it supplied, including likely rescue missions. Furthermore, the long-term isolation of the colonists may take its toll.</p>
<p>When the <a href="http://www.mars-one.com/">Mars One</a> project announced in 2013 that it was looking to recruit four people to send on a mission to colonise Mars, Chris Chambers, a professor of cognitive neuroscience at Cardiff University, <a href="https://www.theguardian.com/science/head-quarters/2013/sep/09/neuroscience-psychology">warned of the psychological risks</a> the colonists would face.</p>
<p>Yet dreams stay alive. According to NASA’s <a href="https://mars.nasa.gov/programmissions/overview/">mission statement</a>:</p>
<blockquote>
<p>Even if Mars is devoid of past or present life, however, there’s still much excitement on the horizon. We ourselves might become “life on Mars”, should humans choose to travel there one day.</p>
</blockquote>
<h2>Earth calling Mars</h2>
<p>Space colonisation dreams are not entirely devoid of economic interests. The international space industry is <a href="http://www.abc.net.au/news/2017-09-24/what-australians-need-to-know-about-space/8979036">said to be worth</a> in the order of some US$400 billion a year, and <a href="https://www.cnbc.com/2017/10/31/the-space-industry-will-be-worth-nearly-3-trillion-in-30-years-bank-of-america-predicts.html">predicted to grow</a> to nearly US$3 trillion over the next three decades. </p>
<p>Space travel and colonisation ideas are mostly promoted by engineers and entrepreneurs who stand to gain from these schemes, but far less so by biologists and medical scientists who understand the terrestrial origin and physiological limitations of the human body.</p>
<p>There can be little doubt that, given modern and future computer and space technologies, space stations could be constructed on Mars, where a few privileged humans may be able to live for periods of time.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-new-space-race-why-we-need-a-human-mission-to-mars-73757">The new space race: why we need a human mission to Mars</a>
</strong>
</em>
</p>
<hr>
<p>Should humans colonise a life-bearing planet, we should ask whether organisms would fare any better than <a href="http://www.biologicaldiversity.org/programs/biodiversity/elements_of_biodiversity/extinction_crisis/">species extinguished on Earth</a>. </p>
<p>The ethical polarity between those dreaming of conquering space and those hoping to defend Earth from global heating and a nuclear calamity could not be greater. </p>
<p>The billions and trillions of dollars required to develop and maintain colonies in space could approach the <a href="https://www.sipri.org/research/armament-and-disarmament/arms-transfers-and-military-spending/military-expenditure">estimated US$1.69 trillion military spending globally</a> in 2016.</p>
<p>As a scientist who examines how a changing climate influences human evolution, I argue that funds on this scale would be better directed at the defence of the lives of <a href="https://www.census.gov/popclock/">more than 7 billion humans</a> on Earth, as well as protection of animals and of nature more broadly.</p><img src="https://counter.theconversation.com/content/87770/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Glikson 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 race may be on to send humans to live on Mars, but is it worth the effort – and the spend – when we have our own problems to deal with on Earth.Andrew Glikson, Earth and paleo-climate scientist, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/787902017-06-08T02:37:10Z2017-06-08T02:37:10ZAir travel exposes you to radiation – how much health risk comes with it?<figure><img src="https://images.theconversation.com/files/172470/original/file-20170606-3698-c0rfrt.jpg?ixlib=rb-1.1.0&rect=86%2C0%2C5216%2C3371&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Captain, we're being pummeled by cosmic rays!</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/passenger-airplane-clouds-travel-by-air-568662646">muratart via Shutterstock.com</a></span></figcaption></figure><p>In 2017, <a href="http://www.independent.ie/business/world/18-million-miles-and-counting-the-globes-top-business-traveller-35666790.html">business traveler Tom Stuker</a> was hailed as the world’s most frequent flyer, logging 18,000,000 miles of air travel on United Airlines over 14 years. </p>
<p>That’s a lot of time up in the air. If Stuker’s traveling behaviors are typical of other business flyers, he may have eaten 6,500 <a href="http://www.airliners.net/forum/viewtopic.php?t=689041">inflight meals</a>, drunk 5,250 <a href="https://doi.org/10.1111/j.1708-8305.2009.00339.x">alcoholic beverages</a>, watched thousands of <a href="http://www.iata.org/publications/store/Pages/global-passenger-survey.aspx">inflight movies</a> and made around 10,000 visits to <a href="http://blog.thetravelinsider.info/2012/11/how-many-restrooms-are-enough-on-a-plane.html">airplane toilets</a>.</p>
<p>He would also have accumulated a radiation dose equivalent to about 1,000 <a href="https://www.radiologyinfo.org/en/info.cfm?pg=safety-xray">chest x-rays</a>. But what kind of health risk does all that radiation actually pose?</p>
<h2>Cosmic rays coming at you</h2>
<p>You might guess that a frequent flyer’s radiation dose is coming from the airport security checkpoints, with their whole-body scanners and baggage x-ray machines, but you’d be wrong. The <a href="http://www.aapm.org/publicgeneral/AirportScannersPressRelease.asp">radiation doses to passengers from these security procedures</a> are trivial. </p>
<p>The major source of radiation exposure from air travel comes from the flight itself. This is because at high altitude the <a href="http://www.altitude.org/why_less_oxygen.php">air gets thinner</a>. The farther you go from the Earth’s surface, the fewer molecules of gas there are per volume of space. Thinner air thus means fewer molecules to deflect incoming <a href="http://www.space.com/32644-cosmic-rays.html">cosmic rays</a> – radiation from outer space. With less <a href="http://www.bbc.co.uk/science/earth/atmosphere_and_climate/atmosphere">atmospheric shielding</a>, there is more exposure to radiation. </p>
<p>The most extreme situation is for astronauts who travel entirely outside of the Earth’s atmosphere and enjoy none of its protective shielding. Consequently, they receive high radiation doses. In fact, it is the accumulation of radiation dose that is the limiting factor for the maximum length of manned space flights. Too long in space and <a href="https://www.nasa.gov/hrp/bodyinspace">astronauts risk cataracts, cancer and potential heart ailments</a> when they get back home.</p>
<p>Indeed, it’s the radiation dose problem that is a major spoiler for <a href="http://www.space.com/34210-elon-musk-unveils-spacex-mars-colony-ship.html">Elon Musk’s goal of inhabiting Mars</a>. An extended stay on Mars, with its <a href="http://www.space.com/16903-mars-atmosphere-climate-weather.html">extremely thin atmosphere</a>, would be lethal due to the high radiation doses, notwithstanding Matt Damon’s successful Mars colonization in the movie <a href="https://www.youtube.com/watch?v=ej3ioOneTy8">“The Martian</a>.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172329/original/file-20170605-16895-1rv1y9u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Air travel means exposure to some radiation… but how much are we talking about?</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/johnjones/5575498919">John Jones</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Radiation risks of ultra frequent flying</h2>
<p>What would be Stuker’s cumulative radiation dose and what are his health risks?</p>
<p>It depends entirely on how much time he has spent in the air. Assuming an <a href="http://hypertextbook.com/facts/2002/JobyJosekutty.shtml">average flight speed</a> (550 mph), Stuker’s 18,000,000 miles would translate into 32,727 hours (3.7 years) of flight time. The radiation dose rate at typical <a href="http://www.telegraph.co.uk/travel/travel-truths/why-do-planes-fly-so-high-feet/">commercial airline flight altitude</a> (35,000 feet) is about <a href="https://hps.org/publicinformation/ate/faqs/commercialflights.html">0.003 millisieverts per hour</a>. (As I explain in my book <a href="http://press.princeton.edu/titles/10691.html">“Strange Glow: The Story of Radiation</a>,” a millisievert or mSv is a unit of radiation dose that can be used to estimate cancer risk.) By multiplying the dose rate by the hours of flight time, we can see that Stuker has earned himself about 100 mSv of radiation dose, in addition to a lot of free airline tickets. But what does that mean for his health?</p>
<p>The primary health threat at this dose level is an increased risk of some type of cancer later in life. Studies of atomic bomb victims, nuclear workers and medical radiation patients have <a href="https://doi.org/10.17226/11340">allowed scientists to estimate the cancer risk</a> for any particular radiation dose. </p>
<p>All else being equal and assuming that low doses have risk levels proportionate to high doses, then an overall cancer risk rate of <a href="http://www.imagewisely.org/imaging-modalities/computed-tomography/medical-physicists/articles/how-to-understand-and-communicate-radiation-risk">0.005 percent per mSv</a> is a reasonable and commonly used estimate. Thus, Stuker’s 100-mSv dose would increase his lifetime risk of contracting a potentially fatal cancer by about 0.5 percent.</p>
<h2>Contextualizing the risk</h2>
<p>The question then becomes whether that’s a high level of risk. Your own feeling might depend on how you see your background cancer risk.</p>
<p>Most people <a href="http://www.who.int/whr/2002/chapter3/en/index4.html">underestimate their personal risk of dying from cancer</a>. Although the exact number is debatable, it’s fair to say that <a href="https://www.cancer.org/cancer/cancer-basics/lifetime-probability-of-developing-or-dying-from-cancer.html">about 25 percent of men ultimately contract a potentially fatal cancer</a>. Stuker’s 0.5 percent cancer risk from radiation should be added to his baseline risk – so it would go from 25 percent to 25.5 percent. A cancer risk increase of that size is too small to actually measure in any scientific way, so it must remain a theoretical increase in risk.</p>
<p>A 0.5 percent increase in risk is the same as one chance in 200 of getting cancer. In other words, if 200 male travelers logged 18,000,000 miles of air travel, like Stuker did, we might expect just one of them to contract a cancer thanks to his flight time. The other 199 travelers would suffer no health effects. So the chances that Stuker is the specific 18-million-mile traveler who would be so unlucky is quite small.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1044&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1044&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1044&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1313&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1313&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172295/original/file-20170605-16869-17w9epo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1313&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Airline personnel are typically the most frequent of fliers.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/bogers/150447878">Bas Bogers</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Stuker was logging more air hours per year (greater than 2,000) than most pilots typically log (<a href="http://work.chron.com/duty-limitations-faa-pilot-17646.html">under 1,000</a>). So these airline workers would have risk levels proportionately lower than Stuker’s. But what about you? </p>
<p>If you want to know your personal cancer risk from flying, estimate all of your commercial airline miles over the years. Assuming that the values and parameters for speed, radiation dose and risk stated above for Stuker are also true for you, dividing your total miles by 3,700,000,000 will give your approximate odds of getting cancer from your flying time.</p>
<p>For example, let’s pretend that you have a mathematically convenient 370,000 total flying miles. That would mean 370,000 miles divided by 3,700,000,000, which comes out to be 1/10,000 odds of contracting cancer (or a 0.01 percent increase in risk). Most people do not fly 370,000 miles (equal to 150 flights from Los Angeles to New York) within their lifetimes. So for the average flyer, the increased risk is far less than 0.01 percent.</p>
<p>To make your exercise complete, make a list of all the benefits that you’ve derived from your air travel over your lifetime (job opportunities, vacation travel, family visits and so on) and go back and look at your increased cancer risk again. If you think your benefits have been meager compared to your elevated cancer risk, maybe its time to rethink flying. But for many people today, flying is a necessity of life, and the small elevated cancer risk is worth the price.</p><img src="https://counter.theconversation.com/content/78790/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothy J. Jorgensen 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>The true radiation risk from commercial flying has nothing to do with security scans. A radiation expert explains how much cancer risk the most frequent of flyers take on when they take to the skies.Timothy J. Jorgensen, Director of the Health Physics and Radiation Protection Graduate Program and Professor of Radiation Medicine, Georgetown UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/561822016-03-14T09:35:01Z2016-03-14T09:35:01ZHow the ExoMars mission could sniff out life on Mars – and what to do next<figure><img src="https://images.theconversation.com/files/114869/original/image-20160311-11277-1e3sq39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Schiaparelli separating from Trace Gas Orbiter.</span> <span class="attribution"><span class="source">ESA–D. Ducros</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>“It (could be) life Jim, but (perhaps) not as we know it.” This is not just a sci-fi catchphrase, but also something some planetary scientists have uttered in response to the discovery of <a href="http://science.nasa.gov/science-news/science-at-nasa/2014/16dec_methanespike/">methane in Mars’ atmosphere</a>. That’s right – scientists believe that some kind of past or present microbial lifeform on Mars could have produced the methane. While it is far from the only possible explanation, it is actually so plausible that a special mission is being sent there to find out.</p>
<p>The first part of what could be a series of missions – the European Space Agency’s <a href="http://exploration.esa.int/mars/">ExoMars Trace Gas Orbiter</a> – launched on March 14 from Baikonur in Kazakhstan and I watched nervously after having spent 13 years working on one of its instruments. Needless to say, it was one of the most exciting and nerve-wracking days of my life.</p>
<h2>Many possibilities</h2>
<p>The mission is an orbiter that will map trace gases in the atmosphere of Mars, over an entire martian year (two Earth years). Of course the methane in the atmosphere doesn’t have to be from microbial life, it could also be caused by cosmic dust or geological processes. ExoMars will test for current geological processes that might be releasing the methane. If all goes well this mission will be followed by a more ambitious ExoMars Rover, designed to test for traces of ancient life, that will launch after 2018. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114867/original/image-20160311-11277-1oohxia.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">Rocket with ExoMars as it is getting ready for launch.</span>
<span class="attribution"><span class="source">ESA - B. Bethge</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The <a href="http://www.sciencedirect.com/science/article/pii/S0019103504002222">first proposed observations</a> of methane plumes on Mars was made over a decade ago, from Earth. The data required a lot of processing, and led to <a href="http://www.sciencedirect.com/science/article/pii/S001910351000446X">controversy</a> among planetary scientists.</p>
<p>According to our current understanding of atmospheric chemistry, methane on Mars should be destroyed relatively rapidly (on the order of a few hundred years). That means it is a gas that we shouldn’t really be seeing on Mars – unless there is some active process creating or releasing it. On Earth, the majority of methane in the atmosphere comes from biological organisms, which raises the question of whether Mars could also host life – past or present. </p>
<p>The orbiter is uniquely designed to map the minute constituents of the Martian atmosphere (such as methane), using a set of highly specialised <a href="https://theconversation.com/explainer-seeing-the-universe-through-spectroscopic-eyes-37759">spectroscopic and imaging instruments</a>. The spectrometers, which can analyse what a gas is made of by measuring the specific wavelengths of sunlight they absorb, are key to measuring the presence of methane and other gases. The relative mixture of the gases observed, along with their composition, can be compared to measurements on Earth in order to provide clues as to whether the origin of the methane could be geological or biological. </p>
<p>I co-led the development of one of these methane-sniffing instruments, <a href="http://mars.aeronomie.be/en/exomars/nomad.htm">NOMAD</a>, with colleagues from the UK and Belgium. Having worked on it for the last 13 years, it has been one of the most important achievements in my career.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/114865/original/image-20160311-11264-17o3x1x.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">The NOMAD spectrometer.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The spacecraft will get to Mars in mid-October. The first thing it will do is to eject a technology demonstrator, the Schiaparelli lander, to prove that Europe can successfully reach the surface of Mars. The lander will provide a few days of surface weather measurements, lasting as long as the batteries on the lander permit. </p>
<p>In the meantime, the orbiter will begin manoeuvres to get into a circular orbit. It will use a fuel-free braking process called “aerobraking” (a somewhat terrifying concept of delicately dragging the spacecraft through the very top of the atmosphere in order to use the friction from the gas molecules to slow it down). This presents another first for Europe, in performing this type of dangerous manoeuvre around Mars. </p>
<h2>What to do if we find life</h2>
<p>So what would happen if we learned that there is microbial life on Mars, or that it has existed there in the past? Well it would only challenge everything we know. We would have to come to grips with not having a unique status in the universe and will have to work out how to include extraterrestrial “life” in our existential or religious beliefs – to name a few.</p>
<p>On a scientific level, there’s a lot at stake. Of course, it would also lead to major new efforts to find life on planets beyond Mars and even beyond our own solar system. </p>
<p>The first challenge if life is ever detected will be to prove that we didn’t bring it there from Earth – a difficult task to achieve. Careful cataloguing of the “bioburden” load on the spacecraft and from the cleanrooms it was assembled in can provide a check on what organisms might have been present on the spacecraft when it left the Earth. Fundamentally though, life that arose beyond the Earth would likely result from subtly different chemical processes, so to find out for sure, a detailed in situ biochemical analysis would be required. </p>
<p>The implications for future exploration of the Solar System are also profound – at present we take great care not to contaminate areas that are considered “special regions of relevance to potential life”; knowing with certainty that life is present will likely impose even stricter cleanliness requirements for any future exploration. In this respect, there lies an interesting debate for the future: should we pursue human exploration of a world that has been found to harbour life?</p>
<p>But even if we don’t find life, the benefits are huge. Ventures like the ExoMars orbiter have taught us to overcome a number of technological challenges, such as miniaturising sophisticated instruments and increasing technical performance, which also underpin many devices we use in everyday life. The skills developed are also of vital importance. Building such a complex spacecraft requires technical, management, software and creative skills that are directly applicable to many different industries and vocations. Pushing the boundaries of what is technically possible to achieve groundbreaking new science is what triggers the leaps that take us forward.</p><img src="https://counter.theconversation.com/content/56182/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Manish Patel receives funding from the Science and Technology Facilities Council (STFC), the UK Space Agency (UK SA), the European Space Agency (ESA) and the European Union (EU).</span></em></p>If we do find life on Mars, it will be difficult to prove that we didn’t bring it there from Earth. An insider talks us through what’s at stake.Manish Patel, Senior Lecturer in Planetary Sciences, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.