Bacterial signs found in Antarctica lake

Bacterial signs found in Antarctica lake
REUTERS

WASHINGTON, DECEMBER 14: Bacteria may lurk underneath the surface of a frozen Antarctic lake, having survived for millions of years without light or outside oxygen, researchers report.

Three separate studies in this week's issue of the journal Science show evidence of bacteria in Lake Vostok, a large lake found only in 1974 in Antarctica. The finding adds support to the possibility that life may exist on other planets. For example, a frozen lake on Jupiter's moon Europa has a slushy lake that scientists think is a likely haven for life.

David Karl of the University of Hawaii and John Priscu of Montana State University looked at ice drilled out from about 11,700 feet below the surface of the lake.

They found DNA from bacteria in what they believe to be lake water that was once thawed and re-froze.

An analysis that Priscu's team did on the DNA indicates that although the bacteria have been isolated for millions of years, they are biologically similar to known organisms.

``Our research shows us that the microbial world has few limits on our planet,'' Priscu said in a statement.

Scientists have found bacteria thriving in ice, in steaming undersea vents and in hot sulphur springs. They have been found living under huge pressure buried deep inside the earth, and far from light at the bottom of the ocean.

``If a similar ice layer is present under the surface of Europa's icy oceans, it may also harbour life,'' Chris Mckay, a planetary scientist at NASA Ames Research Centre in Moffett Field, California, said in a statement.

Radar and sonar mapping suggests that liquid water may exist at the bottom of Lake Vostok, perhaps warmed by the pressure of thousands of feet of ice above or by geothermal sources below.

Russian teams have drilled into the ice covering the lake, but stopped several hundred meters above what was believed to be the level of liquid water, for fear of contaminating it.

International researchers have been debating how best to proceed. ``We don't know what's in Lake Vostok, and we may never know, if we don't get the contamination issues solved,'' Karl said.