tag:theconversation.com,2011:/us/topics/opportunity-rover-5850/articlesOpportunity rover – The Conversation2018-11-06T11:41:10Ztag: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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<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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<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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<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>
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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/410622015-05-05T05:20:38Z2015-05-05T05:20:38ZOpportunity of a lifetime: NASA’s 4,000 days roving Mars<figure><img src="https://images.theconversation.com/files/80126/original/image-20150501-23877-11ydm6v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The rover that could, and still is, running scientific marathons on Mars.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:NASA_Mars_Rover.jpg">NASA/JPL/Cornell/Maas Digital LLC</a></span></figcaption></figure><p>NASA’s exploration rover <a href="http://mars.nasa.gov/mer/home/">Opportunity</a> landed on Mars more than 11 years ago, in January 2004, with what then seemed like ambitious goals: to survive 90 Martian days and drive 600 metres. Opportunity has since <a href="http://mars.nasa.gov/mer/newsroom/pressreleases/20150324a.html">driven the first off-Earth marathon</a> (42.2 kilometres, or just over 26 miles) and just passed through its 4,000th Martian day – known as a sol on the Red Planet, lasting 40 minutes longer than on Earth. </p>
<p>I’ve been fortunate to have been involved with the project from the start, but never would I have thought that besides my wife’s companionship, the other constant in my life would be a robotic rover roaming across the surface of a planet hundreds of millions of kilometres away. To put this in perspective, since Opportunity landed I finished my PhD, started a family, and worked at six institutions in three different countries.</p>
<p>Opportunity found fame and fortune early on. Right where it landed, finely-layered sedimentary rocks revealed evidence that liquid water had once pooled on the Martian surface. Mars is a prime location for the search for life outside our own planet, and water is the most important prerequisite for life. That discovery was hailed as the <a href="http://www.sciencemag.org/content/306/5704/2010.summary">scientific breakthrough of 2004</a> by the journal Science.</p>
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<span class="caption">Looking back at the landing module in Eagle crater, where Opportunity found water.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/Cornell/USGS/ASU</span></span>
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<p>Opportunity then had to become more daring. As only impact craters reveal what is hidden below the sand that covers most of <a href="http://science.nasa.gov/science-news/science-at-nasa/2004/22jan_meridianiplanum/">Meridiani Planum</a> where the rover had landed, the exploration strategy adopted was to hop between craters.</p>
<h2>Crater-hopping on Mars</h2>
<p>From 20-metre-wide Eagle crater via the 150-metre Endurance crater and 800-metre Victoria crater eventually to the 22km-wide Endeavour crater: with each successive crater the next seemed always beyond reach – or so it seemed to us, so far away. It took more than 600 sols to traverse roughly 6km between Endurance and Victoria – and more than 1,000 sols to cover the 21km from Victoria to Endeavour.</p>
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<span class="caption">A 26-mile Martian marathon, and counting, for the 11-year-old rover.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/Cornell/USGS/ASU</span></span>
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</figure>
<p>Opportunity drove in and out of Endurance and Victoria craters – a dangerous, potentially mission-ending undertaking that had to be cleared by NASA headquarters in advance. In the process it took images of and investigated spectacular cliffs of layered sandstone within the craters. More water was discovered at Endeavour, but unlike the previous discovery, this time it was from an earlier Martian eon and was non-acidic and more friendly towards life.</p>
<p>Between craters, Opportunity could investigate rock fragments that had landed on top of the sand sheet and in doing so discovered meteorites among the rubble. Opportunity’s twin rover Spirit and, more recently, NASA’s Mars Science Laboratory rover, <a href="http://www.nasa.gov/mission_pages/msl/index.html">Curiosity</a>, had already observed iron meteorites from a distance. After all, chunks of iron metal glinting in the sun appear otherworldly – even on another world. But only Opportunity was able to take a detailed sample of their composition – and only Opportunity discovered stony meteorites. While the fragments were discovered several kilometres apart, they seem to part of a larger whole – possibly the massive impact that created the Victoria crater.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=148&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=148&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=148&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=186&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=186&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80129/original/image-20150501-23887-ntji94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=186&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Opportunity’s view from the top of Cape Tribulation into the Endeavour crater.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:PIA19109-MarsOpportunityRover-EndeavourCrater-CapeTribulation-20150122.jpg">NASA/JPL-Caltech/Cornell/ASU</a></span>
</figcaption>
</figure>
<h2>Danger everywhere</h2>
<p>There were occasions where it was touch and go whether Opportunity would be able to continue its journey. En route to Victoria crater, the rover <a href="http://www.bbc.co.uk/news/science-environment-26032673">got stuck in a sand dune</a> – subsequently dubbed Purgatory – and it took 38 sols to free itself. On another occasion, one of the notorious Martian dust storms that extend across entire regions blocked out much of the sunlight for days on end, threatening to permanently shut down the solar-powered rover. </p>
<p>However, perhaps the greatest threat to its continued mission is man-made: NASA’s latest budget proposal is not sufficient to continue Opportunity’s operations. While our rover certainly now shows signs age and wear, Opportunity has gathered many friends and admirers during its long journey and there is realistic hope that funding for another mission extension can be found.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80119/original/image-20150501-23877-wxrwme.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">After 4,000 days, looking out to a rocky spire in Mars’ Spirit of St Louis crater.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/Cornell/ASU</span></span>
</figcaption>
</figure>
<p>So, how did Opportunity celebrate its 4,000 days? She drove five meters onto an outcrop peninsula inside <a href="http://www.jpl.nasa.gov/spaceimages/details.php?id=pia19394">Spirit of St. Louis crater</a>, a small crater among the rocks marking the rim of the much larger Endeavour Crater and sniffed the air with her Alpha Particle X-ray Spectrometer. True to her name, Opportunity is still more than capable of making important new discoveries, generating new records with each passing day. It’s been a pleasure working with Opportunity so far, and I hope that she’ll remain part of my life for a while yet.</p><img src="https://counter.theconversation.com/content/41062/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christian Schroeder is a Mars Exploration Rover Science Team collaborator and a former NASA Postdoctoral Program Fellow.</span></em></p>4,000 days on Mars and still going strong: one scientist’s experience of working with Opportunity.Christian Schroeder, Impact Research Fellow, Biological and Environmental Sciences, University of StirlingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/353702014-12-29T21:27:52Z2014-12-29T21:27:52ZNear Earth and far away, it’s been an exciting year in space<figure><img src="https://images.theconversation.com/files/67615/original/image-20141218-31052-1wb459e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Not yet, but soon ... we're getting closer to sending people to Mars.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/samanntran/4884193472">Samantha T./Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>It was an exciting year in space exploration, with mind-blowing triumphs and heart-breaking failures. On Earth, new rockets and spacecraft were tested by space agencies and commercial ventures. </p>
<p>SpaceX, a private company which has sent supplies to the International Space Station (<a href="https://theconversation.com/explainer-the-international-space-station-12565">ISS</a>) on its Dragon/Falcon spacecraft, unveiled a prototype for a <a href="http://www.spacex.com/news/2014/05/30/dragon-v2-spacexs-next-generation-manned-spacecraft">crewed vehicle</a> to much excitement in May.</p>
<p>In July, Russia successfully launched the <a href="http://www.space.com/26872-russia-angara-rocket-launch-vehicle-industry.html">Angara rocket</a> in a sub-orbital flight from Plesetsk. Angara is the first rocket built from scratch since the Soviet era. </p>
<p>NASA tested its <a href="http://www.nasa.gov/orion/">Orion vehicle</a> – uncrewed – in an orbital flight which culminated in a successful splashdown in early December. For many it was a heartening sign that human spaceflight would not be stalled in Low Earth Orbit indefinitely.</p>
<p>The Orion vehicle was not entirely empty, though. On board were a number of objects including a <em>Tyrannosaurus rex</em> fossil, and <a href="http://www.nasa.gov/content/sesame-street-characters-on-board-with-orion/">props</a> from children’s television show Sesame Street: the Cookie Monster’s cookie and Ernie’s rubber duck.</p>
<h2>Don’t take space safety for granted</h2>
<p>Some impediments to spaceflight came not from outer space but the ocean. At NASA’s launch site on Wallops Island, stray boats repeatedly delayed rocket launches. In October, a boat in the exclusion zone caused Orbital Science Corporation’s Antares rocket launch <a href="http://spaceflightnow.com/2014/10/27/errant-boat-scrubs-antares-launch-from-virginia/">to be scrubbed</a>. </p>
<p>The next day, the unthinkable happened. The rocket, carrying the Cygnus craft with over 2000kg of supplies for the ISS, exploded on the launch pad only seconds after lift-off – see the video below. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/aL5eddt-iAo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>A disaster by some lights, but as many commentators pointed out, the fact that no-one was hurt indicated the effectiveness of range safety procedures.</p>
<p>Others were not so lucky. </p>
<p>A test flight of SpaceShipTwo, Virgin Galactic’s suborbital passenger vehicle, <a href="https://theconversation.com/pilots-of-virgin-galactic-spaceshiptwo-deserve-our-admiration-and-honour-33710">exploded</a> after it detached from the launch jet. One pilot parachuted to safety, but another, sadly, did not survive.</p>
<h2>Venus and Mars</h2>
<p>We learnt more about our nearest neighbours, Mars and Venus, in 2014. </p>
<p>The European Space Agency’s Venus Express carried out an audacious dive into previously uncharted areas of the upper atmosphere, and returned safely to orbit. Its watching brief of our planetary twin sister has now <a href="http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Venus_Express_goes_gently_into_the_night">come to an end</a> with the last of its fuel. It’s expected to drift down into Venus’ sulphuric acid clouds over the next few weeks.</p>
<p>Over at Mars, the comet Siding Spring (named after the Australian observatory) hurtled just 140,000km from the red planet in a “<a href="https://theconversation.com/comet-siding-springs-close-encounter-with-mars-draws-near-33083">near miss</a>”. The international fleet of orbiters and rovers was primed to capture images from this rare event.</p>
<p>It was a big year for the <a href="https://theconversation.com/au/topics/curiosity">Curiosity</a> and <a href="https://theconversation.com/an-opportunity-for-life-finding-mars-most-liveable-mud-22168">Opportunity</a> rovers too. On its tenth anniversary, Opportunity became the most-travelled space rover in history, passing the previous record set by Russia’s Lunakhod on the moon. The off-world robotic distance record currently stands at 40km.</p>
<p>For its part, Curiosity was busy gathering evidence that Mars might yet harbour life – geological traces of ancient water, organic carbon molecules, and a <a href="https://theconversation.com/curiosity-catches-a-whiff-of-methane-on-mars-and-a-possibility-of-past-life-35595">surprising sniff of methane</a>.</p>
<h2>Out and about in the solar system</h2>
<p>After ten years of hibernation, the European Space Agency’s comet-chaser Rosetta <a href="https://theconversation.com/relief-as-rosetta-wakes-up-but-still-we-hold-our-breath-22137">woke up</a> and went into orbit around 67P Churyamov-Gerasimenko. The world held its breath as the Philae lander was dropped onto the surface of the comet. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=517&fit=crop&dpr=1 754w, https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=517&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/67618/original/image-20141218-31046-11yo1oa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=517&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">From left to right, images show Philae descending towards and across the comet.</span>
<span class="attribution"><span class="source">ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA</span></span>
</figcaption>
</figure>
<p>Philae’s <a href="https://theconversation.com/sleep-now-for-rosettas-comet-probe-after-a-bouncy-landing-34122">epic bounce</a> across the rough terrain left it in a shaded position under a cliff, with too little sunlight to sustain the solar cells for long. Despite this, both segments of the mission returned <a href="https://theconversation.com/explainer-what-philae-did-in-its-60-hours-on-comet-67p-34289">astonishing data</a> that changed our view of both comets and the Earth. </p>
<p>It’s long been thought that much of the Earth’s oceans are derived from impacts with icy comets; but the composition of 67P’s ice does not match that of Earth.</p>
<p>(And yes, there was <a href="http://zoharesque.blogspot.com.au/2014/11/the-spacecraft-shirt-and-scandal.html">that shirt</a>.)</p>
<p>And finally, another snoozing spacecraft, <a href="https://theconversation.com/rise-and-shine-new-horizons-35332">New Horizons</a>, was woken. The next leg of its mission is a flyby of Pluto, the <a href="http://www.usatoday.com/story/tech/2014/10/02/pluto-planet-solar-system/16578959/">on-again off-again</a> planet we’ve never seen in detail before. In July 2015 we’ll have our first chance to get up close and personal with Pluto before New Horizons travels onwards to the Kuiper Belt.</p>
<h2>Back on earth: power to the people</h2>
<p>The crowd-funding of public space projects gathered pace in 2014 with the launch of Lunar Mission One. </p>
<p>Lunar Missions Ltd proposes to fund a deep-drilling <a href="http://www.lunarmissionone.com/">lunar probe</a> by selling digital “memory boxes”, which will be sent to the moon. This entitles the purchaser to have a say in project decisions. </p>
<p>The <a href="https://theconversation.com/big-brother-on-mars-reality-tv-thats-out-of-this-world-7847">Mars One project</a>, which plans to establish a colony on Mars in 2025, is preparing to select just 24 candidates from the current 600 hopefuls. They’re funding the ambitious project by selling rights to a reality television show like no other, where the “housemates” may actually perish live on air. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Fk0LLX47deA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Hear from some of the candidates.</span></figcaption>
</figure>
<p>The project has received some <a href="http://www.businessinsider.com.au/astronauts-thoughts-on-mars-one-colony-mission-2014-12">vigorous criticism</a> from space professionals such as astronaut <a href="https://theconversation.com/speaking-with-canadian-astronaut-chris-hadfield-30032">Chris Hadfield</a>. But for aspiring Martians like Australian comedian <a href="http://www.abc.net.au/local/stories/2014/10/02/4099026.htm">Josh Richards</a>, it’s about “doing something for humans as a species”. </p>
<h2>Looking forward</h2>
<p>In the next few years, it seems clear that public and private space endeavours will continue to develop in sophistication. </p>
<p>It’s an interesting prospect, as existing <a href="https://theconversation.com/who-owns-space-33222">space treaties</a> weren’t really established with this sort of scenario in mind. But it’s vital that we have more diverse players around the table when determining the future of long term access to space.</p>
<p>We can also look forward to the revision of many of our ideas about the history of this modest solar system we call home. </p>
<p>Already this year we’ve seen the deep terrestrial past opened up with the revelation that human ancestors made symbolic marks <a href="https://theconversation.com/marks-on-an-ancient-shell-lead-to-a-re-think-of-human-history-34957">500,000 years ago</a>. New results from space will open windows into even deeper time.</p>
<p>Perhaps it’s appropriate to finish this wrap-up with a thought from 2014’s science fiction blockbuster, <a href="https://theconversation.com/interstellar-gives-a-spectacular-view-of-hard-science-33991">Interstellar</a>. In the words of Dr Amelia Brand (played by Anne Hathaway), </p>
<blockquote>
<p>Love is the one thing that we’re capable of perceiving that transcends dimensions of time and space. Maybe we should trust that, even if we can’t understand it.</p>
</blockquote><img src="https://counter.theconversation.com/content/35370/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alice Gorman is a member of the National Executive Council of the Space Industry Association of Australia.</span></em></p>It was an exciting year in space exploration, with mind-blowing triumphs and heart-breaking failures. On Earth, new rockets and spacecraft were tested by space agencies and commercial ventures. SpaceX…Alice Gorman, Lecturer, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/221682014-01-23T19:39:38Z2014-01-23T19:39:38ZAn Opportunity for life: finding Mars’ most liveable mud<figure><img src="https://images.theconversation.com/files/39724/original/8nnhqxzv-1390439432.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Opportunity trundles along looking for more evidence of water – and life – on Mars.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>Coinciding with ten years of the NASA <a href="http://mars.nasa.gov/mer10/">Mars Exploration Rover Project</a>, research published today in <a href="http://www.sciencemag.org/content/343/6169/1248097">Science</a> has found some of the oldest evidence of past water on Mars – and confirmed it was ideal to nurture life. </p>
<p>Found in ancient mudstones at Mars’ Endeavour Crater, the geochemical data collected by the <a href="http://marsrovers.jpl.nasa.gov/home/index.html">Opportunity Rover</a> shows that water was almost fresh. It would have been, almost four billion years ago, the most liveable mud on Mars. </p>
<p>Opportunity sampled the Matijevic formation – a grouping of fine-grained, layered rocks enriched with clay minerals – and analyses showed they were the oldest Martian rocks, and had the earliest evidence of water activity, the rover has encountered so far.</p>
<p>Back in 2004, Opportunity discovered rich deposits on hematite, jarosite and round concretions we dubbed “<a href="http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20040318a.html">blueberries</a>”. That was definitive proof that an ocean flowed on Mars. </p>
<p>However, scientists around the world were sceptical about the suitability for life as that water was probably too acidic. Just as you wouldn’t quench your thirst with a glass of vinegar, this water would not make the kind of mud microbes would be able to live in.</p>
<p>But our results indicate that microbes would have found in that place a delight to live in – not too salty, not too acidic, but just right. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=274&fit=crop&dpr=1 600w, https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=274&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=274&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=344&fit=crop&dpr=1 754w, https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=344&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/39712/original/wdbybsgz-1390436493.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=344&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">False-colour image of Matijevic formation rocks. They are 3.7 billion years old and contain evidence that fresh water once flowed over them.</span>
<span class="attribution"><span class="source">Science/AAAS</span></span>
</figcaption>
</figure>
<p>Now we just need to see if there were any microbes there, by searching for any fossils that might hint that Mars was once inhabited and not just habitable. The search, and the fascination, goes on. </p>
<h2>Centuries of wondering</h2>
<p>As a long-term member of the science team guiding research on Mars, I’d like to reflect on what we’re looking for and why it’s worthwhile to keep exploring.</p>
<p>Start by looking at the night sky. Even though we can see just a part of it, the universe has more stars and planets than you could possibly imagine. Yet just a few hundred years ago, we thought we on Earth were at the centre of the universe, putting us in a very special place. </p>
<p>The science done by our first astronomers revealed that, in fact, we were turning around the sun. Later we discovered our sun is <a href="https://theconversation.com/explainer-what-are-stars-15235">just another star</a>, one of many in the universe. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=312&fit=crop&dpr=1 600w, https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=312&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=312&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=392&fit=crop&dpr=1 754w, https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=392&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/39741/original/zhfgvzvq-1390446378.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>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>The first confirmed accounts for another planet beyond our solar system was reported in 1988 by Canadian astronomers <a href="http://adsabs.harvard.edu/doi/10.1086/166608">Campbell, Walker and Yang</a>. The natural questions we now face are: is there life somewhere else in the universe? Or are we alone?</p>
<p>In the thousands of years since the Egyptians and Babylonians first knew of its existence, the red planet has been an object of study and fascination. More recent perspectives on Mars are also interesting to revisit. </p>
<p>In 1877, Italian astronomer <a href="http://www.britannica.com/EBchecked/topic/527306/Giovanni-Virginio-Schiaparelli">Giovanni Schiaparelli</a> saw “continents”, “seas” and “channels” on Mars through his telescope. </p>
<p><a href="http://www.gutenberg.org/files/36/36-h/36-h.htm">The War of the Worlds</a> novel by H G Wells captured public imagination and its famous adaptation by Orson Welles for radio broadcast <a href="http://news.nationalgeographic.com.au/news/2005/06/0617_050617_warworlds.html">in 1938 fooled audiences</a> into thinking Martians were invading us. </p>
<p>More recently still, with the advancement of science, we’ve been in a position to get a more accurate picture of our nearest neighbour. The world of sensors, where my expertise lies, has leaped ahead so we can send compact sensors on spacecraft that gather a wealth of information. </p>
<p>With all this combined international exploration effort, we’ve sent many spacecraft to Mars to study large areas from the air and in minute detail on the ground.</p>
<p>The list of spacecraft reads like a roll-call at school:</p>
<ul>
<li><a href="http://history.nasa.gov/mariner.html">Mariner orbiter</a> in late 1960s</li>
<li><a href="http://www.nasa.gov/mission_pages/viking/">Viking landers</a> during the 1970s</li>
<li><a href="http://www.nasa.gov/mission_pages/mars-pathfinder/">Mars Pathfinder</a> in 1997</li>
<li>in the past decade Mars <a href="http://marsrovers.jpl.nasa.gov/home/index.html">Exploration Rovers</a> Opportunity and Spirit, <a href="http://www.nasa.gov/mission_pages/phoenix/main/">Phoenix</a> and more recently with <a href="http://www.nasa.gov/mission_pages/msl/">Curiosity</a>. </li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=206&fit=crop&dpr=1 600w, https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=206&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=206&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=258&fit=crop&dpr=1 754w, https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=258&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/39723/original/nvyhp9pk-1390439225.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=258&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">Simulated image of Opportunity on ‘Burns Cliff’, Mars.</span>
<span class="attribution"><span class="source">NASA</span></span>
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</figure>
<p>All these landers and rovers on Mars’ surface are being supported by a number of orbiters like <a href="http://mars.jpl.nasa.gov/odyssey/">Mars Odyssey</a>, <a href="http://mars.jpl.nasa.gov/mro/">Mars Reconnaissance</a>, <a href="http://mars.jpl.nasa.gov/mgs/">Mars Global Surveyor</a> and the European Space Agency’s <a href="http://www.esa.int/Our_Activities/Space_Science/Mars_Express">Mars Express</a>. </p>
<p>We also have an Indian mission <a href="https://theconversation.com/indian-mars-mission-beats-neighbours-sniffs-for-methane-19959">Mangalyaan</a> on the way to Mars today, a number of missions being planned for the future like the rover on 2020, <a href="https://theconversation.com/prestige-and-one-upmanship-fuel-chinas-lunar-rover-20874">Chinese attempts</a> to get there as well as the lottery for a <a href="https://theconversation.com/big-brother-on-mars-reality-tv-thats-out-of-this-world-7847">one-way ticket</a> to the red planet. </p>
<h2>Our reason for living</h2>
<p>All this exploration was fuelled by the <a href="http://www.sciencemag.org/content/273/5277/924">1996 analysis</a> of the meteorite ALH84001 in Antarctica. This meteorite came from Mars, has carbonate in its chemistry (carbonate needs water to be formed) and has a number of structures that resemble fossilised bacteria. </p>
<p>Since then the traffic on Mars has never been so intense. </p>
<p>But what are we looking for so intensively on Mars? The answer is everywhere on a full-of-life Earth: water. </p>
<p>Even though some landscape features observed by Mars orbiters provide evidence that liquid water might have flowed on the surface of Mars long ago, surface studies like ours look for direct evidence for mineral deposits created by an interaction with water and rock. The gadgetry on the Mars Rovers is designed to carry out these sophisticated geochemical analyses.</p>
<p>Life, as we know it, depends on water to be formed, sustained and to evolve. It does not mean, however, that life somewhere else in the universe might not depend on another substance. It is much easier to look for something we know so well.</p><img src="https://counter.theconversation.com/content/22168/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paulo de Souza is a collaborating scientist on NASA's Mars Exploration Rover mission.</span></em></p>Coinciding with ten years of the NASA Mars Exploration Rover Project, research published today in Science has found some of the oldest evidence of past water on Mars – and confirmed it was ideal to nurture…Paulo de Souza, Science Leader – Sensor Networks, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/150572013-06-11T05:50:52Z2013-06-11T05:50:52ZAgeing rover finds evidence for an early ocean on Mars<figure><img src="https://images.theconversation.com/files/25259/original/jm5jgpf7-1370795517.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In its 10th year of operation, this rover on Mars is still finding important results.</span> <span class="attribution"><span class="source">NASA JPL</span></span></figcaption></figure><p>After almost a decade of exploring the surface of Mars, American space agency’s rover has found the strongest evidence yet for the presence of water on the red planet. The data comes from the rock “Esperance”, one of the oldest rocks studied on Mars. The clays inside the rock point to the presence of abundant water early in Mars’ history. </p>
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<figcaption>
<span class="caption">A false colour composite showing an area about 70 cm across from which samples, at point “6”, were analysed.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.</span></span>
</figcaption>
</figure>
<p>To obtain this data the rover Opportunity scraped at the rock’s surface to reveal its fresh interior, then used X-rays to analyse the chemicals the minerals inside the rock were made of.</p>
<p>The results showed the interior was high in aluminium and silicon, but low in calcium and iron. The minerals look like swelling clays, just like those found in a muddy puddle on Earth. </p>
<p>Such clays act like sponges in their capacity to soak up water. Actually, the clays form by addition of water and weathering of “primary” silicates, commonly found as volcanic rocks on the surface of Mars. </p>
<p>Opportunity’s results mirror data from Martian rocks at Gale crater obtained by Curiosity rover <a href="http://www.popsci.com/technology/article/2013-03/mars-rover-curiosity-uncovers-watery-past-lots-gale-crater">earlier this year</a>. But they contradict the vast majority of previous mineral analyses, which showed most hydrated rocks were formed of sulfates. Those minerals, such as gypsum, formed in dilute sulfuric acid. Instead, the chemistry reported this week from Esperance implies that the clays formed there had formed in waters that would’ve been drinkable.</p>
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<figcaption>
<span class="caption">A Martian landscape, by Opportunity rover, with late afternoon shadows across Endeavour Crater.</span>
<span class="attribution"><span class="source">NASA/JPL-Caltech/Cornell/Arizona State Univ</span></span>
</figcaption>
</figure>
<p>“This is powerful evidence that water interacted with this rock to change its chemistry and mineralogy in a dramatic way,” Steve Squyres of Cornell University, science team leader of the Opportunity mission <a href="http://www.nytimes.com/2013/06/08/science/space/martian-rock-another-clue-to-a-once-water-rich-planet.html?_r=0">told the New York Times</a>. It is the strongest evidence yet for a past Martian environment that would have been conducive to life.</p>
<p>Speculation linking the origins of life on Earth to the presence of clay minerals has been something of a theme since first suggested in the early 1950s. Swelling clays, like those seen at Esperance, demonstrate the presence of neutral water early in Mars’ history. But at the molecular scale the inter-layer structure of the clay can also act as template to any organic molecules present and, potentially, promote replication of enzymes and proteins, which are necessary for life.</p>
<p>The findings back up earlier theories that the Martian surface once hosted an ocean, covering much of its northern hemisphere. A 2010 paper in the journal <a href="http://www.nature.com/ngeo/journal/v3/n7/abs/ngeo891.html">Nature Geoscience</a> describes ancient Martian coastlines that, 3.5 billion years ago, lay at the edge of an ocean covering around a third of the planet’s surface. </p>
<p>After the landing of Curiosity rover in 2012 with its much upgraded sets of analysis tools, Opportunity’s work acts as independent verification of some of Curiosity’s findings. Opportunity launched on on July 7, 2003 and was designed to operate on Mars only for 90 days after landing. But it has far exceeded expectations, even when its twin rover, Spirit, grounded to a halt back in 2010. </p>
<p>As its tenth anniversary nears and the rover trundles on its explorations by moving to new rocks, these new results demonstrate the ageing rover’s value and make it worthy of celebration.</p><img src="https://counter.theconversation.com/content/15057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Redfern 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>After almost a decade of exploring the surface of Mars, American space agency’s rover has found the strongest evidence yet for the presence of water on the red planet. The data comes from the rock “Esperance…Simon Redfern, Professor in Earth Sciences, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.