Rover Finds “Best Sign Yet” of Microbial Life

NASA says its rover Spirit has discovered "the best evidence yet" of a past habitable environment on the planet's surface. Spirit found a patch of silica-rich soil earlier this year, which scientists believe is a promising sign that hosted at least niche environments that could have potentially harbored life. Spirit has been exploring a plateau called Home Plate, where it discovered silica-rich soil in May.

Researchers are now trying to determine what produced the patch of nearly pure silica. So far, they believe that the deposits must have come from an ancient hot-spring environment or a fumarole, in which acidic steam rises through cracks. On Earth, these types of environments are teeming with microbial life, said rover chief scientist Steve Squyres.

"Whichever of those conditions produced it, this concentration of silica is probably the most significant discovery by Spirit for revealing a habitable niche that existed on in the past," he said.

"The evidence is pointing most strongly toward fumarolic conditions, like you might see in Hawaii and in Iceland. Compared with deposits formed at hot springs, we know less about how well fumarolic deposits can preserve microbial fossils. That's something needing more study here on Earth."

Spirit and its twin rover Opportunity have remained on for much longer than originally planned. Their mission has been extended five times since they landed on opposite sides of the planet in January 2004. The rovers faced their biggest challenge this summer, when a series of dust devils blanketed their solar panels and restricted movement.

Winds finally cleaned off Opportunity, but Spirit is still covered in gunk, and is only working at 42 per cent capacity. NASA scientists said that Spirit will have a very difficult time reaching a resting spot for winter.

"Spirit is going into the winter with much more dust on its solar panels than in previous years," said NASA's John Callas, project manager for the rovers.

"The last Martian winter, we didn't move Spirit for about seven months. This time, the rover is likely to be stationary longer and with significantly lower available energy each Martian day."

Posted by Rebecca Sato

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Is There Life on Mars? NASA Goes Underground to Find Out
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Sources: NASA, The Telegraph

Comments

[Daniel Appleton]

I may be missing something, but why would an abundance of silica be possibly indicative of life on Mars ?

If we could confirmation of a non - carbon based life form, like a viral life form, that would be nice.

[B.B.]

Daniel, yes you are missing something--like the entire point of the post which is that the silica was probably produced by a fumarole, and on Earth these types of environments are rich with microbial life. So, if they are right about the origin of the silica then that means there were at least niche habitats at some point on Mars that would have been "friendly" conditions for life. Not proof of anything, but a promising sign.