Curiosity Detects Methane Spike on Mars   
       
   Dec. 16, 2014: NASA's Mars Curiosity rover has measured a tenfold spike in   
   methane, an organic chemical, in the atmosphere around it and detected other   
   organic molecules in a rock-powder sample collected by the robotic   
   laboratory's drill.   
       
   "This temporary increase in methane -- sharply up and then back down -- tells   
   us there must be some relatively localized source," said Sushil Atreya of the   
   University of Michigan, Ann Arbor, and Curiosity rover science team. "There   
   are many possible sources, biological or non-biological, such as interaction   
   of water and rock."   
       
   http://www.nasa.gov/jpl/msl/pia19088/   
       
   This image illustrates possible ways methane might be added to Mars'   
   atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity   
   Mars rover has detected fluctuations in methane concentration in the   
   atmosphere, implying both types of activity occur on modern Mars. A longer   
   caption discusses which are sources and which are sinks. Image Credit:   
   NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan   
       
   Researchers used Curiosity's onboard Sample Analysis at Mars (SAM) laboratory   
   a dozen times in a 20-month period to sniff methane in the atmosphere. During   
   two of those months, in late 2013 and early 2014, four measurements averaged   
   seven parts per billion. Before and after that, readings averaged only   
   one-tenth that level.   
       
   Curiosity also detected different Martian organic chemicals in powder drilled   
   from a rock dubbed Cumberland, the first definitive detection of organics in   
   surface materials of Mars. These Martian organics could either have formed on   
   Mars or been delivered to Mars by meteorites.   
       
   Organic molecules, which contain carbon and usually hydrogen, are chemical   
   building blocks of life, although they can exist without the presence of life.   
   Curiosity's findings from analyzing samples of atmosphere and rock powder do   
   not reveal whether Mars has ever harbored living microbes, but the findings do   
   shed light on a chemically active modern Mars and on favorable conditions for   
   life on ancient Mars.   
       
   http://www.nasa.gov/jpl/msl/pia19087/#.VJCyu3tG8VQ   
       
   This graphic shows tenfold spiking in the abundance of methane in the Martian   
   atmosphere surrounding NASA's Curiosity Mars rover, as detected by a series of   
   measurements made with the Tunable Laser Spectrometer instrument in the   
   rover's Sample Analysis at Mars laboratory suite. Image Credit:    
   ASA/JPL-Caltech   
       
   "We will keep working on the puzzles these findings present," said John   
   Grotzinger, Curiosity project scientist of the California Institute of   
   Technology in Pasadena (Caltech). "Can we learn more about the active   
   chemistry causing such fluctuations in the amount of methane in the   
   atmosphere? Can we choose rock targets where identifiable organics have been   
   preserved?"   
       
   Researchers worked many months to determine whether any of the organic   
   material detected in the Cumberland sample was truly Martian. Curiosity's SAM   
   lab detected in several samples some organic carbon compounds that were, in   
   fact, transported from Earth inside the rover. However, extensive testing and   
   analysis yielded confidence in the detection of Martian organics.   
       
   Identifying which specific Martian organics are in the rock is complicated by   
   the presence of perchlorate minerals in Martian rocks and soils. When heated   
   inside SAM, the perchlorates alter the structures of the organic compounds, so   
   the identities of the Martian organics in the rock remain uncertain.   
       
   "This first confirmation of organic carbon in a rock on Mars holds much   
   promise," said Curiosity participating scientist Roger Summons of the   
   Massachusetts Institute of Technology in Cambridge. "Organics are important   
   because they can tell us about the chemical pathways by which they were formed   
   and preserved. In turn, this is informative about Earth-Mars differences and   
   whether or not particular environments represented by Gale Crater sedimentary   
   rocks were more or less favorable for accumulation of organic materials. The   
   challenge now is to find other rocks on Mount Sharp that might have different   
   and more extensive inventories of organic compounds."   
       
   Researchers also reported that Curiosity's taste of Martian water, bound into   
   lakebed minerals in the Cumberland rock more than three billion years ago,   
   indicates the planet lost much of its water before that lakebed formed and   
   continued to lose large amounts after.   
       
   SAM analyzed hydrogen isotopes from water molecules that had been locked   
   inside a rock sample for billions of years and were freed when SAM heated it,   
   yielding information about the history of Martian water. The ratio of a   
   heavier hydrogen isotope, deuterium, to the most common hydrogen isotope can   
   provide a signature for comparison across different stages of a planet's   
   history.   
       
   "It's really interesting that our measurements from Curiosity of gases   
   extracted from ancient rocks can tell us about loss of water from Mars," said   
   Paul Mahaffy, SAM principal investigator of NASA's Goddard Space Flight Center   
   in Greenbelt, Maryland, and lead author of a report published online this week   
   by the journal Science   
       
   The ratio of deuterium to hydrogen has changed because the lighter hydrogen   
   escapes from the upper atmosphere of Mars much more readily than heavier   
   deuterium. In order to go back in time and see how the deuterium-to-hydrogen   
   ratio in Martian water changed over time, researchers can look at the ratio in   
   water in the current atmosphere and water trapped in rocks at different times   
   in the planet's history.   
       
   Martian meteorites found on Earth also provide some information, but this   
   record has gaps. No known Martian meteorites are even close to the same age as   
   the rock studied on Mars, which formed about 3.9 billion to 4.6 billion years   
   ago, according to Curiosity's measurements.   
       
   The ratio that Curiosity found in the Cumberland sample is about one-half the   
   ratio in water vapor in today's Martian atmosphere, suggesting much of the   
   planet's water loss occurred since that rock formed. However, the measured   
   ratio is about three times higher than the ratio in the original water supply   
   of Mars, based on assumption that supply had a ratio similar to that measured   
   in Earth's oceans. This suggests much of Mars' original water was lost before   
   the rock formed.   
       
   Credits and more information:   
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   Curiosity is one element of NASA's ongoing Mars research and preparation for a   
   human mission to Mars in the 2030s. Caltech manages the Jet Propulsion   
   Laboratory in Pasadena, California, and JPL manages Curiosity rover science   
   investigations for NASA's Science Mission Directorate in Washington. The SAM   
   investigation is led by Paul Mahaffy of Goddard. Two of SAM instruments key in   
   these discoveries are the Quadrupole Mass Spectrometer, developed at Goddard,   
   and the Tunable Laser Spectrometer, developed at JPL.   
       
   The results of the Curiosity rover investigation into methane detection and   
   the Martian organics in an ancient rock were discussed at a news briefing   
   Tuesday at the American Geophysical Union's convention in San Francisco. The   
   methane results are described in a paper published online this week in the   
   journal Science by NASA scientist Chris Webster of JPL, and co-authors.   
       
   A report on organics detection in the Cumberland rock by NASA scientist   
   Caroline Freissenet, of Goddard, and co-authors, is pending publication.   
       
   For copies of the new Science papers about Mars methane and water,   
   visit:http://go.nasa.gov/1cbk35X   
       
   For more information about Curiosity, visit http://www.nasa.gov/msl and   
   http://mars.jpl.nasa.gov/msl/   
       
   Learn about NASA's Journey to Mars at http://www.nasa.gov/conten   
   /nasas-journey-to-mars/   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
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