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Curiosity Confirms That Mars Was Once Capable of Harboring Life

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The Curiosity Rover has just accomplished exactly what it was set out to do. According to NASA scientists, the probe's latest analysis of a Martian rock sample shows that ancient Mars was once capable of supporting living microbes. It’s not confirmation of life; rather, it's evidence for the Red Planet's historical potential to host life.

Last month, Curiosity drilled some samples out of a sedimentary rock near an old river bed in Gale Crater. This geological area used to feature a series of stream channels, leaving behind finely grained bedrock indicative of previously wet conditions.


Using the rover’s onboard instrumentation, NASA scientists analyzed these samples to detect some of the critical elements required for life, including sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon. Back here on Earth, microbes use sulfates and sulfides as sources of energy.

And indeed, this was the the very essence of the mission. Curiosity is basically serving as a robotic geologist, equipped with such tools as the Sample Analysis at Mars (SAM) system and the Chemistry and Mineralogy X-Ray Diffraction/X-Ray Fluorescence Instrument (CheMin) which it uses to identify and measure abundances of various minerals on Mars.


As geobiologist Roger Summons of MIT told io9 just prior to the mission, Curiosity can perform basic geochemistry as it evaluates the Martian landscape and atmosphere for its potential to harbor life at some point in the planet’s past.

"Once we have more geologic information, then we can start to make valid hypotheses about the early conditions for life on Mars,” he told us.

And indeed, that information is starting to come in, and it looks very promising.


Data returned from SAM and CheMin suggest that the ancient river system that Curiosity finds itself in, or what might have been an intermittently wet lake bed, could have provided enough chemical energy and other conditions suitable for microbial life. Rocks found in the area are comprised of a fine-grained mudstone containing clay and sulfate minerals, along with other chemicals. Moreover, this area wasn’t oxidizing, acidic, or salty.

According to NASA scientist David Blake, clay minerals make up at least 20% of the composition of the sample taken by Curiosity. This clay could have formed when water on Mars mixed with other minerals.


In addition, scientists detected a mixture of oxidized, less-oxidized, and un-oxidized chemicals, compounds that can provide the energy required to sustain microbial life.

Moving forward, Curiosity will explore the Yellowknife Bay area in anticipation of its venture towards Mount Sharp where NASA scientists expect the probe to find more clay and sulfate minerals.


Source and images: NASA.