Lake Vosok, situated near the center of Antarctica, is water lying beneath a sheet of ice over two miles deep – it remains liquid due to geothermal heat underneath. Its existence was discovered in late 1996 and since that time, researchers have been eager to drill down to retrieve water samples. Caution was advised, however, as scientists worried that drilling attempts might cause material from the surface to contaminate the water or samples received. One prior attempt to drill down to the lake by a British team failed leaving the Russians to give it a try. They made it to within 130 meters of the surface of the lake back in 1998, but halted work when scientists around the world expressed concerns about the lack of planning to prevent contamination.
( via phys.org )