Lake Vostok in Antarctica isn't like most of the world's other lakes. You can't see it from surface level, because it's been buried under two miles of ice for the past 15 million years. And unlike other bodies of water that recycle their contents fairly quickly, the water in Lake Vostok only recycles about once every 13,000 years from some unknown source. It's under too much pressure from all the ice above it to freeze, but it can't easily escape either, and it's uncontaminated by human activity or chemicals.
That's why scientists think it may be a treasure trove of extremophiles - that is, organisms which have evolved to live in the harshest, most inhospitable conditions.
VIDEO: Why Do We Go to Antarctica?
Studies of ice from just above the liquid lake have revealed dozens of types of bacteria and fungi, and also genetic fragments that might suggest the presence of fish and crustaceans, according to a 2013 Nature news article. A Russian scientist also reported that the ice contained a previously unknown type of bacteria, whose DNA was different from other known species. But other scientists disputed those finds, saying that the samples had been tainted by anti-freezing chemicals used to keep the drill working.
In late January, researchers managed to drill down to the lake again, and this time, they say they've devised a method to obtain an uncontaminated 1-liter sample of the lake's water, according to RT.com. That may help resolve the mystery of whether life exists in Lake Vostok.
NEWS: Robot Sub Maps Antarctic Ice in 3D
Since the lake was discovered in 1996, scientists have used radar to explore it and the ice above it, which took thousands of years to accumulate.
There are about 200 other lakes under Antarctica, which actually contains about 70 percent of the world's entire fresh water supply.