AP file Russian researchers at the Vostok station in Antarctica pose for a picture after reaching Lake Vostok in February 2012. Scientists hold a sign reading "05.02.12, Vostok station, boreshaft 5gr, lake at depth 3769.3 metres." The researchers now report that they have brought up fresh samples from the borehole.





Russian researchers say they have brought up fresh samples of clear ice from Antarctica's Lake Vostok, a huge reservoir of freshwater more than 2 miles (3.2 kilometers) beneath the surface.

Lake Vostok could contain water and perhaps living organisms that have been sitting undisturbed in the deep dark for up to 20 million years. The drilling operation also could set a precedent for far more ambitious efforts to find life beneath the ice of the Jovian moon Europa or the Saturnian moon Enceladus.

Because of the potential for contamination, scientists have been taking extreme care at Lake Vostok, which is situated 800 miles (1,300 kilometers) from the South Pole in East Antarctica. A year ago, the Russian drilling team reached the lake and brought up water samples. Some of the water was even served to Vladimir Putin, who was then Russia's prime minister and is now the country's president. But it wasn't clear whether those samples were actually from the lake or from the glacier above the lake, the Russian news service RIA Novosti reported.

This year's drilling operation is aimed at bringing up samples that can be linked more definitively to the lake itself.

"The first core of transparent lake ice, 2 meters long, was obtained on Jan. 10 at a depth of 3,406 meters," Russia's Arctic and Antarctic Research Institute said in a statement. "Inside it was a vertical channel filled with white bubble-rich ice."

The institute said that drilling operations would be extended another 24 meters with the existing cables, and that new cables were being delivered to the Vostok research station. The core samples were to be subjected to chemical and biological analysis.

Lake Vostok is about 160 miles (250 kilometers) long and 30 miles (50 kilometers) wide, making it the largest of Antarctica's nearly 400 subglacial lakes. Last year's drilling operation drew up samples from a depth of 12,366 feet (2.34 miles, or 3,769 meters). In October, Russian team members reported finding no native life within those samples. They said the only microbes they detected were traced to contaminants from the drilling oil.

The lake could serve as a laboratory for studying what Antarctica's climate and ecosystem was like millions of years ago. It may contain creatures unlike any that exist today. And as ambitious as all that sounds, the Vostok operation is seen as a mere warmup for future sampling missions to Europa, Enceladus and perhaps other icy moons in the solar system.

Planetary scientists see ample evidence that liquid water exists on those worlds, miles beneath the icy surface, and astrobiologists have theorized that internal heat may provide enough energy for organisms living within those hidden oceans.

Correction for 1:30 p.m. ET Jan. 14: I initially described Vostok station as 800 miles east of the South Pole, but that's not quite right: All directions from the South Pole are north, as commenters have pointed out. There is an "east" and "west" to the continent, and Vostok happens to be in East Antarctica. I've changed the reference to the location accordingly.

More about the mysteries beneath the ice:

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.