Scientists have long speculated that Mars might have played host to microbial life in an earlier era. Now that it's certain water exists on the Red Planet, they're trying to grow some microbes that could live there.
The microbe Methanosarcina barkeri is known to grow on Earth in places where oxygen and nutrients are scarce and conditions are harsh — much like they are on Mars. University of Maryland scientist Kevin Sowers thinks that M. barkeri could survive the various climate extremes of Mars because it already often does so on Earth. According toAstrobiology Magazine:
"We are pushing the envelope to see what the organism's limits are," Sowers says. They will use DNA microarrays and 3D tomography to see how the cells respond and what benefit the outer shell confers.
Sowers and his colleagues are interested in M. barkeri because it excretes methane as part of its respiratory process, which some believe might be the source of the methane in the Martian atmosphere. Sowers and colleagues are investigating how the microbe reacts to the specific extremes of Mars, including huge temperature and humidity swings and scarce nutrients.
M. barkeri might well be up to the challenge of surviving unassisted on Mars: in addition to exhaling methane, it can digest methanol and acetate and, lacking that, can create its own organic molecules from other molecular elements it finds in its environment. Unlike spore-forming microbes, when conditions get too harsh to support even microbial life, M. barkeri forms a tough outer layer not unlike connective tissue in higher vertebrates.
Once tested on Earth, it's even possible that M. barkeri could be part of a future expedition to the Red Planet along with some human passengers in need of more technological assistance.
Tough Microbe Has The Right Stuff for Mars [Astrobiology Magazine]
[Image via the Microbe Wiki]