Buried over two miles beneath the East Antarctic Ice sheet lurks Lake Vostok — an isolated body of subglacial water, removed from the rest of the world for more than twenty million years. Now, Russian researchers are just a few meters of ice away from entering an environment unlike any we've ever seen... at least, not here on Earth.
Vostok is thought to harbor conditions similar to those of Jupiter's moon Europa and Saturn's moon Enceladus, and the discovery of life in the lake's inky depths would significantly strengthen the prospect of discovering life on either of these icy bodies. Does support for the existence of exobiological life thrive in Lake Vostok? After 20 years of drilling, we're about to find out.
Lake Vostok's is an environment characterized by extremes. Geothermal heat from the Earth's interior radiates from the lake's bottom, its waters maintain their liquid state. On its surface rest thousands of meters of crushing ice, driving the pressure skyward and the freezing point of the lake's waters below zero degrees celsius. These ice sheets also serve to insulate Vostok from the coldest surface temperatures on Earth, while infusing it with oxygen at concentrations fifty times higher than is typical of freshwater lakes on the planet's surface. It is a system entirely deprived of light. Whatever nutrients exist are likely found in only the smallest of quantities.
All these factors add up to make Vostok (the largest and deepest of over 200 freshwater lakes trapped beneath Antarctica's monstrous ice sheet) one of the most inhospitable places on the planet. Scientists describe Vostok's conditions, in particular, as "oligotrophic."
If life exists in Vostok's waters, it will almost certainly be some form of extremophile — an organism suited to living in conditions that would kill all but a fraction of a percent of all other life forms on Earth. And given the lake's extreme isolation, scientists suspect that any life we encounter will be unlike anything we've ever seen.
Such life forms would shed light not only on the evolutionary processes of organisms here on Earth, but the feasibility of life on other cosmic bodies like Europa and Enceladus — both of which are believed to harbor sub-surface waters of their own. By this time next year, Russian researchers hope to have lowered a submersible, remote-operated vehicle down the drill shaft and into Vostok's depths to explore, and even collect samples from the lake's bottom. What we learn from these experiences on Earth could serve us in the not-so-distant future, perhaps while plumbing the frozen depths of Europa.
Accessing Vostok's waters, however, will not be easy. According to the Washington Post, Russian scientists are within 40 feet of the lake's expected water line, and have stopped drilling to prepare for the numerous risks posed by drilling through the final layers of ice, including contamination of the lake by the drilling equipment, and the escape of pressure through Vostok's newly introduced geophysical bleeder valve.
These are just some of the challenges the Russians will face if they are to break through to the lake within the week as planned. But time is not on the drillers' side. Winter is setting in, and the researchers could be forced to abandon their work exactly like they did one year ago, when they came within 20—40 meters of the lake's surface.
Read more about the efforts to reach Lake Vostok at The Washington Post.