Giant drill probes land time forgot

Published on Saturday 7 March 2009 19:44

A FROZEN, pitch-black world buried under two miles of ice for millions of years could hold the answer to one of the greatest mysteries in the universe.

Scientists have been given the go-ahead to drill through the Antarctic ice sheet and search a prehistoric lake trapped beneath for signs of life.

If the British team find what they are looking for in 300ft-deep Lake Ellsworth it will be one of the greatest discoveries of modern times, providing further evidence that life can exist on distant worlds without a sun's light and heat.

The scientists are led by Professor Martin Siegert, head of the School of GeoSciences at Edinburgh University, the principal investigator and an Antarctica expert.

The team will use specially-designed drilling equipment to explore the lake in West Antarctica, which is thought to be the size of Windermere and have a bed covered in thick sediment. Experts believe it is a strong candidate for supporting microbial life.

Siegert said: "It is a dark, cold place that has been sealed from the outside world, and it's likely to contain unique forms of life.

"Microbiologists think deep-water subglacial lakes are unique extreme environments where unusual microbes might adapt and survive. These environments may be the closest analogues on Earth to (Jupiter's moon] Europa, which has a thick icy crust above a liquid ocean," he added.

"We hope to discover more about how life can exist in extreme environments and how Antarctica has changed in the past, which might help us to understand more about other places on earth."

The 6m project will begin in 2012 when the team break into the lake with a pair of probes designed to capture living organisms, or the chemical signs of life.

It will be the first time any nation has explored the subglacial lakes of Antarctica, of which there are around 150.

There have been concerns the project could pollute the area and ruin the lake. But the probes are especially designed to be sterile to prevent microbial contamination from the surface, by using hot water to melt the ice as the drill penetrates the ice sheet.

The British team, which has been working on the project for a decade, has been in a race against a similar Russian project to penetrate Lake Vostok in east Antarctica. However the Russian project has run into difficulties.

The subglacial lakes of Antarctica remain unfrozen due to geothermal heat rising from deep underground and the immense pressure of the ice pushing down on the water which acts as an insulating blanket. The water remains liquid at -1 to -2C.

It is thought that lifeforms may have survived despite the total darkness by consuming organic detritus and other nutrients that accumulated in the sediment many millennia ago.

The focus of the search for extraterrestrial life has been on Europa because liquid water is necessary for life and Europa is believed to have an ocean of water beneath a thick crust of ice.

Nasa plans to send a fleet of spacecraft to Europa within the next decade to survey the moon.

Although the surface of Europa is at -160C it is thought the water underneath is prevented from freezing by tectonic friction caused by the tug of gravitational forces between Jupiter and its dozens of moons.

Mineral-rich hot water vents would be spewing nutrients into Europa's ocean, providing any life that is there with food and energy.