March 13th, 2013 by James Ayre
NASA’s Mars rover Curiosity recently used its rock drill to take a sample of the material inside of a Martian rock for the first time. Now that an analysis has been done on that material it is very clear that Mars could have very likely supported microbial life in its ancient past.
The analysis confirmed and identified the presence of many if the key ingredients to life as we know it. Nitrogen, hydrogen, sulfur, oxygen, phosphorus and carbon, were all present in the powder that Curiosity took from the inside of a sedimentary rock found near an ancient stream bed on Mars last month.
“A fundamental question for this mission is whether Mars could have supported a habitable environment,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “From what we know now, the answer is yes.”
Evidence of this earlier more-habitable environment comes from “data returned by the rover’s Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine-grained mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty,” NASA stated in a recent press release.
The bedrock where the sample was obtained is located within a very old network of stream channels that descend from the top of Gale Crater. The bedrock “is fine-grained mudstone and shows evidence of multiple periods of wet conditions, including nodules and veins.”
“Clay minerals make up at least 20 percent of the composition of this sample,” said David Blake, principal investigator for the CheMin instrument at NASA’s Ames Research Center in Moffett Field, Calif.
The clay minerals were formed as a result of the interaction of “fresh water” with igneous minerals that are Ali present in the sediment, including olivine. “The reaction could have taken place within the sedimentary deposit, during transport of the sediment, or in the source region of the sediment. The presence of calcium sulfate along with the clay suggests the soil is neutral or mildly alkaline.”
“Scientists were surprised to find a mixture of oxidized, less-oxidized, and even non-oxidized chemicals, providing an energy gradient of the sort many microbes on Earth exploit to live. This partial oxidation was first hinted at when the drill cuttings were revealed to be gray rather than red.”
“The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulfates and sulfides that indicate a possible chemical energy source for micro-organisms,” said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Curiosity will soon be taking more drill samples in order to confirm these results.
“We have characterized a very ancient, but strangely new ‘gray Mars’ where conditions once were favorable for life,” said John Grotzinger, Mars Science Laboratory project scientist at the California Institute of Technology in Pasadena, Calif. “Curiosity is on a mission of discovery and exploration, and as a team we feel there are many more exciting discoveries ahead of us in the months and years to come.”
Curiosity will remain working in the “Yellowknife Bay” area for at least a few more weeks, and then will begin its long drive up Mount Sharp. “Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions.”
Image Credits: NASA/JPL-Caltech/Cornell/MSSS
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