Less than 600 frozen miles from the South Pole, Russian scientists in Antarctica say they have successfully drilled down to Lake Vostok, a mysterious body of water sealed two miles beneath the polar ice cap.
They have been trying to reach it for two decades. Sampling it, they say, may yield important clues about the history of Earth, and perhaps other worlds as well.
Valery Lukin, the head of Russia's Arctic and Antarctic Research Institute (AARI) in charge of the mission, said in a statement today that his team reached the lake's surface Sunday. They had been cautious until now, saying they wanted to check readings from sensors on their remote-controlled drill.
"There is no other place on Earth that has been in isolation for more than 20 million years," Lev Savatyugin, a researcher with the AARI who was involved in preparing the mission, told The Associated Press. "It's a meeting with the unknown."
Lake Vostok, 160 miles long and 30 miles wide, has only been seen on radar until now. The Russians, who run the Vostok research station at the surface, said their plan was for the drill to break through the ice into the hidden lake, and automatically withdraw so as not to contaminate the water below.
Scientists watching the project said they worried that 66 tons of lubricants and antifreeze used in the drilling might spoil the pristine lake. But Lukin said in his statement that about 1.5 cubic meters of kerosene and freon poured into tanks on the surface from the boreshaft, proof that the lake water streamed from beneath, froze, and blocked the hole.
"Great God! This is an awful place," wrote the English explorer Robert Falcon Scott when he reached the South Pole a century ago last month. Scott and his four comrades, beaten to the pole by Roald Amundsen's Norwegian expedition, died in the cold as they tried to trudge back to safety. And the climate is actually worse at Vostok station, where the Russians once measured a surface temperature of 129 degrees F below zero. (The current temperature, the Russians report, is about 40 below; it is late summer there.)
Lake Vostok is believed to be warmed by geothermal energy. But why drill to it, beyond feeling the tug of mystery?
"According to our research, the quantity of oxygen there exceeds that on other parts of our planet by 10 to 20 times. Any life forms that we find are likely to be unique on Earth," said Sergey Bulat, the chief scientist of Russia's Antarctic Expedition, as quoted by Russian Reporter magazine.
There are other scientists who are doubtful. Too much oxygen, they argue, could actually be toxic to life. So Lake Vostok could turn out to be unique -- the first place found on Earth where there is water in liquid form but nothing living.
This could have implications for the search for life elsewhere in the solar system. Jupiter's moon Europa and Saturn's moon Enceladus have both been seen by NASA probes to have icy crusts, but, apparently, enough heat from inside to raise at least the possibility of hidden oceans. Europa in particular has been hopefully labeled as a possible home for extraterrestrial life. Space scientists would like to know a lot more about them. Could Lake Vostok, half a billion miles closer, offer clues as to what lies beyond, in the cold reaches of space?
The Russians, despite the cold of Antarctica, despite limited money for scientific research, have kept drilling down toward Lake Vostok. What will they find in the water there?
"It's like exploring another planet, except this one is ours," said Columbia University glaciologist Robin Bell.
The Associated Press contributed to this report.