Having just completed the tortuous 48-hour journey from the South Pole to the US west coast, John Priscu is suffering from more than his fair share of jet lag. But his tiredness can't mask the excitement in his voice. After weeks of intense field work in Antarctica, he and his team have become the first to find life in a lake trapped under the frozen continent's ice sheet.
“Lake Whillans definitely harbours life,” he says. “It appears that there lies a large wetland ecosystem under Antarctica’s ice sheet, with an active microbiology.”
The lake in question is a 60-square-kilometre body of water that sits on the edge of the Ross Ice shelf in West Antarctica. To reach it, Priscu, a glaciologist at Montana State University in Bozeman, and his team had to drill down 800 metres of ice.
They arrived at their goal on 28 January, when their environmentally clean hot-water drill broke through to the lake's surface. What they found was a body of water just 2 metres or so deep — much shallower than the 10–25 metres seismic surveys had suggested, although Priscu notes that the lake may well have deeper spots.
The team put a camera down the borehole to make sure that the borehole was wide enough for sampling instruments to be deployed and returned safely. It was, and over the next few days, the scientists collected some 30 litres of liquid lake water and eight sediment cores from the lake’s bottom, each 60 centimetres long.
What precious stuff they had retrieved soon became clear under the on-site microscope. Both water and sediment contained an array of microbes that did not need sunlight to survive. The scientists counted about 1,000 bacteria per millilitre of lake water — roughly one-tenth the abundance of microbes in the oceans. In Petri dishes, the bacteria show a “really good growth rate”, says Priscu.
There is definitely hope for Europa. I have to wonder about Lake Vostok though.