( CNN ) -- Russian scientists briefly pierced the two-mile-thick veil over a freshwater lake hidden beneath Antarctica 's ice sheet for millions of years , polar researchers announced Wednesday . Scientists hope samples of Lake Vostok , a body the size of Lake Ontario , will yield signs of previously undiscovered life and new clues about the history of the planet . The lake is believed to have been covered by ice for up to 30 million years . Russian researchers completed the drilling effort Sunday , reaching the lake at a depth of 3,769 meters ( 2.3 miles ) into the ice , the St. Petersburg-based Arctic and Antarctic Research Institute reported . When the ice above the lake was breached , lake water was sucked up into the bore and froze , the Russians said . That will allow researchers to take samples back to the surface without contaminating the lake below , they said . Columbia University geophysicist Robin Bell said the Antarctic ice sheet has covered the lake for an estimated 15 million to 30 million years . The Russians have been trying to reach Lake Vostok for more than a decade , and the institute said Russian Natural Resources and Ecology Minister Yuri Trutnev was on hand for the final steps . `` They consider it the equivalent of getting to the moon , '' Bell told CNN . The lake 's existence was confirmed in 1996 . Earlier drilling by scientists from multiple nations produced ice cores that contain trapped atmospheric gases , which scientists have used to measure changes in the concentration of carbon dioxide over time . Bell said former Vice President Al Gore cited Vostok ice cores in the 2006 documentary `` An Inconvenient Truth , '' about the threat of global climate change . And peering into the long-hidden waters could give scientists a glimpse of primordial life forms never before catalogued . `` Every place we 've looked on Earth , we 've come up with life , '' Bell said . `` So it would be kind of surprising if we did n't find life there . '' The earlier drillings stopped short of the lake , in part because scientists were n't confident about getting to the water without contaminating it . University of Hawaii oceanography professor David M. Karl said areas of those cores that were near the lake -- accreted ice , or ice derived from the lake itself -- contained a few viable bacteria that became active under incubation . `` There were a very few microorganisms , but in fact there were microorganisms , '' said Karl , who found them in a half-meter sample of the accreted ice in the late 1990s . He said that could mean viable microorganisms exist in the lake . It 's also possible nothing is alive there , in part because no sunlight gets to the lake through ice that thick . But fossil microorganisms may be found , and microorganisms could be living off other sources of energy , such as geothermal , he said . `` There also could be living microorganism living off of previously stored energy from sediments , '' Karl said . Bell said that to reach the water , the Russians drilled to within about 10 meters ( 33 feet ) of the bottom of the ice , then withdrew the drill bit and used a heat probe to bore the rest of the way . The effort was designed so that when the ice sheet was breached , lake water was drawn upward a short distance . That water quickly froze , closing off the lake and allowing scientists to take samples without introducing any contaminants , Bell said . `` The international community has tried to work collaboratively to try to make sure things are done as safely as possible , and it 's in the Russians ' interests to do it right , '' she said .
NEW : Scientists hope samples will yield previously undiscovered life , evidence of planet 's history . Russia says its scientists have found the lake under 2 miles of ice . The lake has been buried beneath a thick sheet of ice for millions of years .