Page 39 - 200812 - The 'X' Chronicles Newspaper - December 2008

39 Amazing Mars: Discoveries in 2008 39 Amazing Mars: Discoveries in 2008 Amazing Mars: Widespread water Cycling climate Amazing Mars: Discoveries in 2008 Another MRO study, which looked at a Understanding the climate of Mars, both Discoveries in 2008 By Andrea Thompson type of clay mineral called phyllosilicates (clays past and present, is also important to gauging By Andrea Thompson are formed in the presence of water), suggests the planet's potential habitability, and various Humans have pondered the mysteries of that water was more widespread on Mars' missions have contributed to the picture of Mars for thousands of years, with one question surface than was previously thought. Mars' climate this year. eliciting particular interest: Is there life up Phoenix was able to confirm the It was known that Mars' climate changes there? presence of an underground layer of water ice in as its orbital axis wobbles (changes angles), While there is no good evidence that life Mars' arctic plains (first suggested by with the poles and equator alternately warming ever existed on Mars, the tantalizing possibility observations from NASA's Mars Odyssey and cooling. Evidence of this showed up in new that the planet may once have been able to orbiter made in 2002). Scientists are now poring MRO images that suggest past equatorial support life garnered some of the strongest over the data from Phoenix's analysis of arctic glaciers and repeated episodes of glaciation on support yet this year, as the orbiters, landers and dirt to see if that ice layer might once have been Mars. MRO has even found current glaciers rovers recently sent to investigate our rusty liquid during past periods when Mars' orbital tilt outside of Mars' polar regions, buried beneath neighbor gathered key evidence of the planet's made the north pole a warmer place. aprons of debris (which keep the ice from watery past, climatic shifts and other points of Preliminary results suggest this may have been sublimating), which likely formed under a geology and chemistry that could have impacted the case, as Phoenix detected the signatures of different climate regime than currently governs the emergence of any potential Martian life. clays in the surface dirt. the planet. Some of the missions that made key Whether or not any of the water held in Variations in sediment layers observed findings this year: the polar ice caps turns to liquid below the by MRO also provide evidence for the effects NASA's Phoenix Mars Lander studied surface is not known, but another MRO study that Mars' changing climate can have on the the surface of the Martian arctic plains from its this year found that the crust below the northern surface of the planet. landing on May 25 until it lost power on Nov. 2. polar cap was exceptionally thick, which Above the surface, the European Space NASA's Mars Reconnaissance Orbiter suggests that the planet is colder than previously Agency's Mars Express orbiter detected dry ice (MRO) has used its high-resolution instruments thought, meaning that if that does turn to liquid, (or frozen carbon dioxide) clouds in Mars' to probe the planet's surface from orbit and just it's likely much deeper than anticipated. atmosphere that cast shadows on the surface finished its two-year primary mission. below and affect regional weather and wind NASA's Mars Exploration Rovers, Harsh or benign? patterns. Spirit and Opportunity, marked their fourth Phoenix also observed clouds overhead, anniversary on the planet in January (the rovers While water has clearly been present in which increased as the landing site transitioned will celebrate their fifth anniversary in January Mars' past, it's less clear how hospitable that into northern hemisphere winter. The lander 2009). water would have been to any potential Martian even observed snow falling from high in the air microbes or other primitive life forms. and frost forming at the surface. Water, water everywhere? Opportunity data, newly analyzed this Phoenix also monitored the cycling of year, shows water in its roving area would have water between the surface and the atmosphere While many conditions are considered been very briny — while the finding doesn't rule from night to day. In warmer, wetter times, important for life to arise on a planet or moon, out life entirely, even the toughest halophiles more water droplets may have stuck to the the one that is essential for life as we know it is (salt-loving) organisms known on Earth would surface, creating a film of water that some microbes are capable of living in. liquid water. So NASA scientists trying to have trouble thriving in these salt-choked While these findings have filled in some answer the question of habitability have used waters, scientists said. pieces in the puzzle of Mars' past, there are still the mantra "follow the water" for their missions. Previous findings from the MER rovers many holes left to fill in. The MER rovers, Though Mars is bone dry today, also painted an unfriendly picture for life in scientists have known for some time that another way: They detected acidic dirt with MRO and other orbiters and the upcoming Mars Science Laboratory (delayed until 2011 in features including what look like gullies, river plenty of sulfates — indicative of volcanic November) and MAVEN missions will all aim beds, and possibly lakebeds suggest that water activity — that suggest that the water that once to find more clues that will help scientists put once flowed on its surface. existed in the areas of the planet they are But when that water flowed, whether or exploring (closer to the equator) was acidic and together a bigger picture of Mars or Mars' past, not it was hospitable to life, and whether it was therefore less hospitable to life. especially its habitability. the result of rainfall, melting ice or groundwater But a recent analysis of MRO data found were still big questions — questions that pockets of the surface that may have escaped More ‘X’ TRIVIA... Phoenix, MRO and other missions have helped the acid bath. The orbiter detected signatures of to at least partially answer this year. carbonates, which dissolve in acids; their - Why don’t dogs eat citrus fruit? They make Several processes have been implicated presence indicates that some areas of the surface their own vitamin C. in forming water-related surface features, were less hostile to life and could have - There are 12 letters in the Hawaiian alphabet. including groundwater and potentially oceans preserved signatures of any life that may have - Humans are the only mammals that cry tears. (as evidenced by MRO images), a lake inside a persisted there. - The real Daniel Boone detested coonskin caps. crater (also found by MRO), possible Phoenix also found signs of a more -No kidding - the cigarette lighter was invented hydrothermal springs (also MRO), massive pleasant place for potential life, with its before the match. flash floods, and possibly even rainfall instruments indicating that the dirt at its landing - Five Jell-O flavors that flopped: celery, coffee, (including some evidence from rovers). Large site is alkaline (a surprise to scientists given the cola, apple and chocolate. bodies of water that persisted for a long time are acidic nature of the surface elsewhere). - Alexander Graham Bell insisted the best way prime places for life to have potentially Samples of Martian dirt dug up by to answer the phone was by saying “Ahoy!” emerged that scientists can further explore. Phoenix also showed signs of perchlorate, a - In the Middle Ages, having ants in the house Evidence had originally suggested that compound that could act as an energy source for was a sign of good luck. much of the precipitation, flooding and other Martian microbes. - In 1920, the average check at a diner was 28 actions by water ended after the first billion MRO also detected a curious signature cents. years or so of Mars' 4.5 billion year history, but that could indicate life was once present on the - According to the real estate industry, the one study from this year used MRO's HiRISE surface: reduced iron. On Earth, reduced (or average person looks at 8 houses before buying. imager and found light-toned deposits that ferrous) iron is generally formed by - Wilt Chamberlain is 7’1” tall. His parents were suggest the planet was wet for a billion years microorganisms, though other processes, such 5’8”. longer still. Opal deposits detected by MRO as reaction with organic carbon brought by a - Poll result: 25% of Americans believe in also suggest a longer wet period for Mars. comet impact could account for the signature. ghosts; 10% say they’ve seen one.