That quest is taking NASA research scientist Richard Hoover inside the Arctic Circle to far-eastern Siberia where he and colleagues from the Russian Academy of Sciences will spend two months harvesting ancient ice. Using drilling equipment that can extract ice cores from as deep as 50 meters below the surface, the team hopes to find preserved fossils of ancient microorganisms some perhaps in ice formed a million years ago.

Hoover, a solar physicist at NASA's Marshall Space Flight Center who has become captivated by astrobiology, is scheduled to leave Wednesday to hunt for extremophiles -- microscopic organisms that thrive in extreme environments.

Microbes that are able to live under extreme pressures or at superheated or sub-zero temperatures, or that can stay alive in some sort of dormant stage for thousands of years could yield clues to where analagous extraterrestrial life forms might be found.

Searching ice samples for signs of life is not new for Hoover. Earlier this year he discovered 30,000-year-old microbes in ice cores from the Alaskan arctic. He also helped analyze samples provided by a Russian colleague, Elena Vorobyova, of Moscow State University. Vorobyoya, who will be working with Hoover during the upcoming expedition, provided ice samples from Antarctica, that were analyzed using Marshalls electron microscope. The samples were found to contain samples of ancient bacteria, fungi, and diatoms (a kind of single-celled algae).

The sites Hoover and his colleagues will target during the upcoming expedition have been selected for their promise to harbor ice samples that are older than one million, and perhaps as many as 2 million, years old, Hoover told space.com today.

The team will drill at sites near Tiksi and Chersky at the far northern reaches of the Asian continent, and along the bank of the Kolyma River.

If Hoover and his colleagues are able to discover where the ice-loving microbes tend to concentrate and what features support microbial life, scientists will be able to better target any search for signs of extraterrestrial life, Hoover said.

Astrobiologists look to Martian polar icecaps, or to Jupiter's fiery volcanic moon Io as places where life might be viable. Perhaps the most promising to many scientists is the Jovian moon Europa, which has a frozen surface of water ice that could cover a global ocean.

What excites Hoover most about the search for ice-bound microbes, he said, is the possibility of finding viable ancient organisms in deep freeze. Vorobyova and her colleague David Gilichinsky previously discovered a moss that had remained alive but dormant for 40,000 years in the permafrost of northeastern Siberia, according to NASA.

Some scientists believe that similar life forms could survive travel through space, perhaps on a frozen comet, or icy asteroid, and might act to seed life on planetary bodies from place to place in space.

The Siberian expeditions U.S. sponsor is NASAs Astrobiology Institute, an interdisciplinary consortium of scientists and academics dedicated to studying the origins of life in the universe. Formed just last year, much of the institutes investigation is aimed at finding and studying terrestrial life that lives on the fringes of the hospitable world.