If we’re looking for pristine environments for life, Antarctica offers much. More than 150 subglacial lakes have been discovered beneath the ice sheet, isolated from the surface for long periods and possibly home to species that have never before been observed. From November 2007 to February 2008, a subglacial lake named Lake Ellsworth was studied by a four-person team that used seismic and radar surveys to map the lake’s depth and take other measurements that made clear its potential for exploration. Their blog is archived here, and it makes for good reading.
Image: A DeHavilland Dash-7 flying near the British Antarctic Survey research station at Rothera. The station is 1630 kilometers southeast of Punta Arenas, Chile, and served as a staging area for the Lake Ellsworth studies of 2007-2008. Credit: Natural Environment Research Council.
Europa, anyone? Well, there are certain resemblances. If the thickness of the ice on Europa is still controversial, we know for a fact that Lake Ellsworth’s ice is three kilometers thick, covering a lake that is 150 meters deep. Lake-floor sediments here could offer clues to Earth’s past climate. The water remains liquid not only because of the insulating effect of the ice above, but because of heat from below coming up through the bedrock. Of course, Lake Ellsworth will require drilling to get into its uncontaminated water in the hunt for life. Europa, as we’ve seen recently, may not — a lander exploring near older cracks in Europan ice may turn up evidence for life-forms exposed to the surface by periodic melting.
Lake Vostok, in east Antarctica, is probably the best known subglacial lake, but they’re all interesting because the water within them may be as old as the ice sheet above. In Lake Ellsworth’s case, that means on the order of 150,000 years and perhaps more. The success of the recent studies have now led to a new effort involving researchers from a host of British institutions and funded by the UK’s Natural Environment Research Council. In the 2012-2013 Antarctic winter season, they’ll try to reach pristine lake water to sample it for life and extract sediments from the lake bed.
David Blake is head of technology and engineering at the British Antarctic Survey:
“This project is a great scientific challenge and the technology required to drill 3 km through the ice without contaminating the lake is equally ambitious. Over the next few years we will build a hot water drill and probe, and make preparations to transport a sophisticated operation deep into the interior of West Antarctica. We really are at the frontiers of scientific exploration.”
That bit about not contaminating the lake says it all. This is tricky business — recall that we eventually dispatched the Galileo Jupiter orbiter to a crushing end within the depths of Jupiter’s atmosphere, all because we wanted to be sure that it would never impact Europa. If a spacecraft that had been exposed to space for almost fourteen years was still thought a potential contamination hazard, how do we get a probe through Lake Ellsworth’s ice without introducing surface life? Clearly, the progress of the Lake Ellsworth effort will be worth watching. You can track developments at the Exploration of Subglacial Lake Ellsworth site.