Friday, July 3, 2009

Ultramicrobacteria on Mars?

Recently I read an article in the National Geographic News about extremely tiny microbes - 10 to 50 times smaller than E coli - reviving after being frozen for 120,000 years at the bottom of a Greenland glacier. They were extracted from a layer of ice two miles deep. Now consider that planetary icebox, Mars, and the speculation about bacteria, or other tiny forms of life, that might have appeared during that planet's all too brief wet period where saline lakes and perhaps seas spread across a planetary surface washed by rain and dusted with snow. As the atmosphere thinned the lakes evaporated and the seas froze and much of the water migrated to the polar caps Mars became a dusty snowball. Glaciers still exist on the surface, some hidden beneath mantles of dust, and some right out on the surface within craters. The next Mars rover, Curiosity, will be exploring and sampling an area hoped to have preserved chemical traces of such early life. A fossil would be too much to hope for, but Earthly discoveries like these make you wonder what ancient surprises might lurk in an Martian deep freeze.