Bacteria Could Survive In Martian Soil

Dagondanum writes "Multiple missions have been sent to Mars with the hopes of testing the surface of the planet for life — or the conditions that could create life. The question of whether life in the form of bacteria (or something even more exotic) exists on Mars is hotly debated, and still lacks a definitive yes or no. Experiments done right here on Earth that simulate the conditions on Mars and their effects on terrestrial bacteria show that it is entirely possible for certain strains of bacteria to weather the harsh environment of Mars." Perhaps this is something that will be tested further in a few years by the Mars Science Lab, also known as "Curiosity" and (as reader Nova1021 points out) "the Mars Action Hero."

Re:Survive and reproduce?

[careysub]

To my knowledge many species of bacteria can survive indefinitely in practically any environment, but not while actively metabolizing. I am curious whether any of the species the article is talking about could actually survive and spread, if they would just stick around for a while and die out, or if they would only survive in a dormant state.

Bacteria definitely exist on Earth that can reproduce under conditions that exist somewhere on Mars, an example are the chemosynthetic bacteria found deep underground and are nourished by geothermal energy: http://www.planetary.org/news/2006/1027_Bacteria_Found_Thriving_Deep.html [planetary.org]

What this study is establishing is whether it is possible to recover viable organisms from the near-surface soil. Such organisms might thrive below the reach of the surface lander's probes, but still have inactive spores brought to near the surface through water welling up from deeper down (and possibly other processes). Evidence of surface water outflows have been found in various spots on Mars.

Re:FP

[reverseengineer]

No, it looks like the same definition- the bacteria that survived did so by forming desiccated, nondividing endospores. The article mentions that the bacteria which didn't protect themselves with the endospore stage died within minutes. The two strains of bacteria they tested are of particular importance because they have been known to survive the Jet Propulsion Lab standard decontamination procedures, and so could take a trip to Mars. This paper [plosone.org] describes some of the DNA repair mechanisms that B. pumilus uses to survive under adverse conditions.

Re:What are we waiting for?

[Metasquares]

That's just the thing - we might not see it until it's too late. One strong gamma ray burst could just wipe us out and we wouldn't even know it was coming until the moment it arrived. It's not about responding to an imminent threat, but being prepared to recover from one that may occur at a later time. Right now all of our data is on one hard drive. We need to make a backup.