December 12, 2011
Water On Mars Could Mean The Planet Is Habitable
Scientists from the Australian National University have found that “large regions” of the Red Planet could actually sustain terrestrial life.
The results are based on the scientists´ findings that extensive regions of the sub-surface of Mars could contain water and be at comfortable enough temperatures to support at least microbial life.
In the study -- An Extensive Phase Space for the Potential Martian Biosphere -- published today in the Astrobiology Journal, researchers from ANU´s Planetary Science Institute modeled Mars to evaluate its potential for harboring inhabitable water and found much more than they were expecting.
Charley Lineweaver, co-lead researcher of the study, compared models of temperature and pressure conditions on Earth with those on the Red Planet to estimate how much of Mars was actually livable for Earth-like organisms.
Lineweaver and his team found that three percent of Mar´s volume -- compared to just one percent of Earth´s -- was habitable, though mostly underground.
“What we tried to do, simply, was take almost all of the information we could and put it together and say ℠is the big picture consistent with there being life on Mars?´,” Lineweaver told AFP. “And the simple answer is yes... There are large regions of Mars that are compatible with terrestrial life.”
“Our models tell us that if there is water present in the Martian sub-surface then it could be habitable — as an extensive region of the subsurface is at temperatures and pressures comfortable for terrestrial life,” said co-lead author of the study, PhD student Eriita Jones.
“We know that there is a hot, deep biosphere on Earth that extends to around five kilometers (3.1 miles). If there is a hot deep biosphere on Mars, our modeling shows that it could extend to around 30 kilometers (18.6 miles),” added Lineweaver.
Lineweaver said where previous studies had taken a “piecemeal” approach by examining particular sites on Mars for signs of life, his study was more of a “comprehensive compilation” of the entire planet using decades of data.
Frozen water has been found at Mar´s polar regions and the ANU study examined how much of the planet could sustain Earth-like microbial life. The low-pressure environment of Mars means water cannot exist as a liquid on the surface and will vaporize. But Lineweaver said underground the conditions are optimal, where the weight of the soil gives added pressure water needs to maintain liquidity.
He also said it would be warm enough, at certain depths, for bacteria and other micro-organisms to thrive due to heat from the planet´s core. On the surface, however, the average temperature is minus 81 degrees Fahrenheit.
“Our conclusion is that the best way to find water — or potentially microbes — on Mars is to dig. Sadly, NASA´s Curiosity Rover, which is scheduled to land on Mars in August, has a limited capacity to scratch the surface to 10 or 20 centimeters (4 to 8 inches),” Lineweaver told the French news agency.
The Planetary Science Institute at ANU is a joint initiative of the Research School of Astronomy and Astrophysics and the Research School of Earth Sciences.
Image Caption: The tenuous atmosphere of Mars, visible on the horizon in this low-orbit photo. Credit: NASA
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