Russian scientists used this 5-G drilling machine to reach Lake Vostok in Antarctica. The team hit the lake Sunday at the depth of 12,366 feet in the central part of the continent. The lake may allow a glimpse into microbial life forms that existed before the Ice Age. / 2007 photo by Pavel Teterev/Associated Press
By Vladimir Isachenkov

Associated Press

MOSCOW -- After more than two decades of drilling in Antarctica, Russian scientists have reached a gigantic freshwater lake hidden under miles of ice for about 20 million years -- a pristine body of water that may hold life from the distant past and clues to the search for life on other planets.

Finally touching the surface of Lake Vostok, the largest of nearly 400 subglacial lakes in Antarctica, is a major discovery avidly anticipated by scientists around the world.

Valery Lukin, the head of Russia's Arctic and Antarctic Research Institute, who oversaw the mission, likened the endeavor to the race to the moon won by American scientists over the Soviets in 1969.

"I think it's fair to compare this project to flying to the moon," he said Wednesday.

The Russian team hit the lake Sunday at the depth of 12,366 feet about 800 miles southeast of the South Pole in the central part of the continent.

The lake may allow a glimpse into microbial life forms that existed before the Ice Age. Scientists say they believe that microbial life may exist in the dark depths of the lake despite its high pressure and constant cold -- conditions similar to those expected to be found under the ice crust on Mars, Jupiter's moon Europa and Saturn's moon Enceladus.

"In the simplest sense, it can transform the way we think about life," NASA's chief scientist Waleed Abdalati said via e-mail.

U.S. and British teams are drilling to reach their own subglacial Antarctic lakes, but Columbia University glaciologist Robin Bell said those lakes are smaller and younger than Vostok, which is the big scientific prize.

Lake Vostok is 160 miles long and 30 miles across at its widest point, similar in area to Lake Ontario. It's kept from freezing into a solid block by a mammoth crust of ice that acts like a blanket, keeping in heat generated by geothermal energy underneath.

The technological challenges of drilling through the ice crust in the world's coldest environment have made the project unique.

Temperatures at the Vostok Station have registered the coldest recorded on Earth -- reaching 128 below. Conditions were made even tougher by its high elevation, more than 11,000 feet above sea level, resulting in thin oxygen.

The effort, however, has drawn strong fears that 66 tons of lubricants and antifreeze used in the drilling may contaminate the lake. Bell said the Russian team was doing its best to avoid contamination, but some other scientists were nervous.

University of Colorado geological sciences professor James White was among those who urged caution about drilling into subglacial lakes.

"Lake Vostok is the crown jewel of lakes there," White said by telephone. "These are the last frontiers on the planet we are exploring; we really ought to be very careful."

Lukin said Russia had waited for several years for international approval of its drilling technology before proceeding to reach the lake.

The drilling began in 1989 and dragged on because of funding shortages, equipment breakdowns, environmental concerns and severe cold.

Russian scientists reached the lake just before they had to leave at the end of the Antarctic summer, as plunging temperatures halted air links. Work is to continue in December.