Last week, I wrote about the possibility of putting a permanent base on the moon. This week we’re boldly going where no man has gone before.
About 4,000 meters under a glacier, to be exact.
On Tuesday February 5th, Russian scientists announced that they had finally breached the ice sheet separating us from Lake Vostok, a subglacial lake in Antarctica. Why do we care? Because Lake Vostok has been sealed off from the rest of the world for more than 15 million years. The life we find there will be different from anything we’ve ever seen.
Whatever lives in Vostok has been evolving separately from the rest of the world for a very, very long time, and in an extreme environment at that. What will we find in the dark, cold depths of the Antarctic?
Scientists have already found micro-organisms in the ice above the lake, and expect to find much more once they get a rover into the liquid water. The most exciting material to collect is the sediment at the bottom, which will have been relatively unmoved and untouched in these 15 million years.
The implications go beyond our own planet. Jupiter and Saturn both have moons (Europa and Enceladus, respectively) with deep ice crusts covering liquid water. These subglacial lakes, warmed by the planet they sit on instead of by the sun, probably have a lot in common.
Discovered using space-based radar in the early 90’s, Vostok is actually just the largest of a network of 200 subglacial lakes in the area. It measures about the same area as Lake Ontario, but with almost three times the volume. At its warmest the water in the lake is estimated to be at -3º C. It maintains a liquid state because of the incredibly high pressure of the ice above it.
Vostok is a textbook example of an oligotrophic environment, an extreme habitat with few nutrients to support life. Researchers have found it to be supersaturated with nitrogen and oxygen, its levels over fifty times those of a normal lake. This high gas concentration is also due to the lake’s pressured environment.
This high pressure makes an already difficult drilling job all the more dangerous. The drill team already has to work only during the Antarctic summer, limiting their visits to one or two months at a time each year. Even if they’ve truly broken to the surface of the lake this time, they won’t be able to continue the mission until December of 2012, when the water is warm enough to liquify again.
Some worry that the high gas content of the lake will cause a catastrophic geyser when the last layer of ice is broken. If this did occur, the unique organisms living in Vostok could be lost forever. At this time, the Russian team is optimistic, and plans to sent a robot down for samples in December.