Antarctic Microbes Colonize under Mars-like Conditions:NASA News
May 15, 2010 7 Comments
A team of researchers from Canada, New Zealand, and the United States have identified additional microbes living in the soils of Antarctica’s Dry Valleys The iceless basins mimic the surface of Mars in that they are extraordinarily cold and arid. Temperatures average around -30 to -35 degrees Celsius (roughly -20 to -30 degrees Fahrenheit). Precipitation is negligible, seldom topping 10 mm (four tenths of an inch) in a year. The scientists also say that the soils and rocky debris of the valleys formed under weathering, glacial, and geologic conditions similar to those on Mars.
The Dry Valleys have been described as “the edge of life.” Only microbes and a few nematodes inhabit it. On their recent expedition, says researcher William C. Mahaney, “we went to the iron-rich [soils], where we thought we’d find lots of microbes, because microbes need iron for physiological processes. And we sampled the lower-down, high-salt [soils], where we thought we would find few microorganisms. We found just the opposite.” The scientists discovered abundant fungi and bacteria in soil so salty that water in it can sometimes stay liquid to Â56 degrees Celsius (Â69 degrees Fahrenheit). This supercooling process isn’t completely understood. Astrobiologists generally think that liquid water can’t exist at the surface of present-day Mars (although a few dispute this), and liquid water is necessary for life. However, team member Victor R. Baker suggests that this same supercooling might also take place in the Martian soil, making liquid water available to microscopic life.
The team says their investigation “opens up the possibility of [present] life on Mars and the possible positions within a soil where it might be found.” They believe this information could be useful in planning future missions to Mars. Establishing the limits that life can endure and searching for past or present life elsewhere in our solar system are among of astrobiology’s primary goals.