[dropcap]A[/dropcap] newly discovered batch of microbial life has been found in a sealed brine lake located beneath 65 feet of Antarctic ice, providing scientists with a rare opportunity to examine how life may cope with extreme conditions on other planets.
A team of University of Illinois scientists have reportedly identified a diverse ecosystem in Lake Vida, an underground lake located in Antarctica. The findings, detailed in the Proceedings of the National Academy of Sciences, shed light on the extreme limits at which life can live not just on Earth, but possibly alien worlds, including Mars, say scientists.
“Lake Vida is a model of what happens when you try to freeze a lake solid, and this is the same fate that any lakes on Mars would have gone through as the planet turned colder from a watery past,” says Peter Doran of the University of Illinois, Chicago, co-author of the study. “Any Martian water bodies that did form would have gone through this Vida stage before freezing solid, entombing the evidence of the past ecosystem.”
To investigate life in the sub-Antarctic lake the team of researchers collected samples of brine from ice cores. The results showed reduced and oxidized compounds as well as high levels of molecular hydrogen. To sample the unique environment researchers worked under secure, sterile tents on the lake’s surface to keep the site and equipment clean as they drilled ice cores, collected samples of the salty brine residing in the lake ice, and then assessed the chemical qualities of the water and its potential for harboring and sustaining life.
Geochemical analyses suggest that chemical reactions between the brine and the underlying iron-rich sediments generate nitrous oxide and molecular hydrogen. The latter, in part, may provide the energy needed to support the brine’s diverse microbial life.