For the first time, scientists report, they have found bacteria living in the cold and dark deep under the Antarctic ice, a discovery that might advance knowledge of how life could survive on other planets or moons and that offers the first glimpse of a vast ecosystem of microscopic life in underground lakes in Antarctica.
A network of hundreds of lakes lies sandwiched between the continents land and the ice that covers it, and scientists had thought that it could harbor life. The discovery is the first confirmation.
It transforms the way we view the Antarctic continent, said John Priscu of Montana State University, a leader of the scientific expedition.
After drilling through a half-mile of ice into the 23-square-mile, 5-foot-deep Lake Whillans, the expedition scientists recovered water and sediment samples that showed clear signs of life, Priscu said, speaking from McMurdo Station in Antarctica on Tuesday. They saw cells under a microscope, and chemical tests showed that the cells were alive and metabolizing energy.
Priscu said that every precaution had been taken to prevent contamination of the lake with bacteria from the surface or the overlying ice. In addition, he said, the concentrations of life were higher in the lake than in the borehole, and there were signs of life in the lake bottoms sediment, which would be sealed off from contamination.
Much more study, including DNA analysis, is needed to determine what kind of bacteria have been found and how they live, Priscu said. There is no sunlight, so the bacteria must depend on organic material that has drifted into the lake from other sources for instance, decaying microbes from melting glaciers or on minerals in the rock of the Antarctic continent.
Our stateside DNA sequence work will tell us who they are, Priscu said of the microbes, and, together with other experiments, tell us how they make a living.
But he said he was confident that the researchers had achieved the first glimpse of an ecosystem that had been completely unknown.
Its the worlds largest wetland, Priscu said.