Bacteria hints at life on other planets

Researchers have found traces of a heat-loving bacterium that may live beneath a frozen lake in Antarctica.

Lake Vostok is covered by more than 3km of ice and must have been isolated from our planet's atmosphere for millions of years.

The bacteria appeared in sediment mixed with a core of ice drilled by Russian and French researchers.

The heat-loving, or thermophilic, bacterium may suggest that hydrothermal vents exist on the lake floor.

Meanwhile, a new ice core drilled this season may reveal whether there is also life in the lake itself.

Hundreds of lakes exist beneath the thick Antarctic ice sheet, but with an area of 14,000 sq km Vostok is by far the largest.

It has never been penetrated, but scientists know it is there through radar measurements taken from above.

Lost world

Because Vostok sees no sunlight and has not been in contact with the atmosphere since it was covered with ice around 15 million years ago, scientists hope it might reveal the kind of life that could exist on other planets, or on Europa, the ice-covered moon of Jupiter.