Courtesy NASA Ames/Chris McKay Scientists working at the bottom of the world have discovered a hardy strain of bacteria living comfortably in a salty lake buried under 20 meters of ice in East Antartica.
The body of water, called Lake Vida, is nearly 3000 years old and might as well be situated on one of Jupiter’s moons. It’s by no means a vacation destination. Sunlight no longer reaches it. The bacteria living in it survive in a pitch-black environment, with sub-freezing temperatures, and in waters that contain seven times the amount of salt found in seawater,
"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 co-leader Peter Doran of the University of Illinois, Chicago. Scientists from NASA, the Desert Research Institute in Reno, and several other institutions make up the expedition team.
The microorganisms belong to a species new to science. They thrive in a briny mix rich in hydrogen, nitrous oxide, and carbon - not exactly your normal chemical stew for gracious living – but somehow the bacteria manage to extract energy from the concoction. The researchers think the high salt content interacting with minerals in lake sediments may be responsible for the unusual chemistry.
The discovery of life in Lake Vida could help in our search for life on other planets or beneath the surfaces of their icy moons.
"This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn's moon Enceladus and Jupiter's moon Europa," said Chris McKay, of NASA’s Ames Research Center, and co-author of the paper published online recently in the Proceedings of the National Academy of Sciences Early Edition.
Other subsurface lakes in Antarctica are also under investigation, Lake Vostok, which I posted about previously, and Lake Ellsworth in West Antarctica. Both lakes are millions of years older, and buried under kilometers of ice rather than just meters. It will be interesting to see if some form of life can manage to survive in those even more extreme conditions.