The first analysis of powder samples drilled out from the inside of once water-soaked rock shows Mars was a suitable place for microbial life to evolve, scientists with NASA's Mars rover Curiosity mission said Tuesday.
Among the chemicals discovered inside the rock, called "John Klein," were sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon, all key ingredients for life.
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The analysis showed that water which once soaked the rock had a neutral pH – not too acidic and not too salty.
The findings indicate that if organics were present, they could have been preserved. That assessment remains under way.
"The key thing here is this an environment a microbe could have lived in and might have even prospered in," lead scientist John Grotzinger, with the California Institute of Technology, told reporters during a press conference at NASA headquarters in Washington, D.C., and on a conference call.
Scientists don't know how old the rock is, nor how it formed, but they suspect it is at least 3 billion years old and that the site's habitability period likely coincides within a couple of hundred million years of the first preserved record of life on Earth.