View Full Version : Plausibility of Martian Microbes

2004-Apr-27, 05:13 PM
Plausibility of Martian Microbes (http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid= 941&mode=thread&order=0&thold=0) - based on a National Academy of Sciences report

Did results from the Viking mission in the late 1970s not suggest that Mars was probably devoid of life? That was the accepted interpretation at the time, based on the results of three experiments that tested for biological activity and the absence of organic molecules in the surface materials. However, this conclusion may be open to some debate based on recent advances in our understanding of biology.

2004-Apr-27, 05:16 PM
Interesting. I remember reading a few months back that had the Vikings landed in the Andes they wouldn't have found life on Earth... #-o

2004-Apr-28, 02:35 AM
Not the Andes--the Atacama Desert.


Mars-like Atacama Desert could explain Viking 'No Life' Result
November 11, 2003

A team of scientists from NASA, the Universidad Nacional Autonoma de Mexico, Louisiana State University and several other research organizations has discovered clues from one of Earth's driest deserts about the limits of life on Earth, and why past missions to Mars may have failed to detect life.

The results were published this week in Science magazine in an article entitled "Mars-like Soils in the Atacama Desert, Chile, and the Dry Limit of Microbial Life."

NASA's Viking missions to Mars in the 1970s showed the martian soil to be disappointingly lifeless and depleted in organic materials, the chemical precursors necessary for life. Last year, in the driest part of Chile's Atacama Desert, the research team conducted microbe-hunting experiments similar to Viking's, and no evidence of life was found. The scientists called the finding "highly unusual" in an environment exposed to the atmosphere.

"In the driest part of the Atacama, we found that, if Viking had landed there instead of on Mars and done exactly the same experiments, we would also have been shut out," said Dr. Chris McKay, the expedition's principal investigator, who is based at NASA Ames Research Center, Moffett Field, Calif. "The Atacama appears to be the only place on Earth Viking would have found nothing."

During field studies, the team analyzed Atacama's depleted Mars-like soils and found organic materials at such low levels and released at such high temperatures that Viking would not have been able to detect them, said McKay, who noted that the team did discover a non-biological oxidative substance that appears to have reacted with the organics -- results that mimicked Viking's results.

"The Atacama is the only place on Earth that I've taken soil samples to grow microorganisms back at the lab and nothing whatsoever grew," said Dr. Fred A. Rainey, a co-author from Louisiana State University, who studies microorganisms in extreme environments.

2004-Apr-28, 02:44 AM
Hmmmm, so what would be the chances of hitting the only two spots on Mars without any trace of life?

2004-Apr-28, 03:14 AM
Yeah. I'm reminded of some sci-fi story or other, where the visiting aliens land in some place like Las Vegas and assume that all Earthlings are like that, and flee the planet in dismay. :lol:

So the landers landed in the only two spots on Mars that are like the Atacama--the rest of the place is more like Ohio, but without all the Republicans. :D