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The last untouched realm of life on the Earth is about to be opened up for scientific exploration. These are the subglacial lakes of Antarctica - vast, dark bodies of prehistoric water, which have been sealed under kilometres of ice for hundreds of thousands or millions of years. Andrew Luck-Baker looks at the science and the ambitious plans behind their exploration.

Russian scientists are poised to penetrate the largest, Lake Vostok, with a conventional drill next January. They have been drilling their way towards the lake top for several years now, located at their research station where the lowest temperature ever measured on the planet was recorded, -90 degrees C.

But the British may beat them when it comes to profound discoveries about subglacial lakes. In December this year, a UK team will set up its own extraordinary ice 'drilling' operation, three kilometres above Lake Ellsworth on the other side of the frozen continent. Lake Ellsworth is roughly the size of Lake Windermere. The UK's audacious plan entails melting a narrow 3.5 kilometre long hole into that lake with a jet of near- boiling water. The scientists will deploy a probe into the depths of the hidden lake to take readings and samples from top to bottom. This stage of NASA-style mission is scheduled for December 2012. It involves scientists and engineers from the British Antarctic Survey and a number of British universities.

Between them, the projects could discover unique forms of microbial life which are adapted to a combination of extreme cold, crushing pressure and no light. The findings may reveal the limits at which life can exist and the tricks it has evolved to survive there both here on Earth and on other planets. The projects will also act, it is argued, as tests for technologies for seeking for extraterrestrial life on ice-encrusted water-moons such as the planet Jupiter's Europa.

The British programme will also drill into the muds and sands at the bottom of Lake Ellsworth and bring samples back to the surface. Those sediments promise to give us a much clearer picture of what climate conditions would bring about the collapse of Antarctica's great ice sheets and resulting catastrophic global sea level rise. The sediments should contain information about this because they themselves formed when Antarctica in that region was too warm to host a thick ice sheet.

The engineering effort behind the project is daunting. The project will set up a powerful boiler on the ice surface in a place where the air temperature is routinely at -20 degrees C. That initially involves transporting 60 tonnes of hardware and 55 tonnes of diesel fuel 300 kilometres through the icy Ellsworth Mountains. Part of the cargo is a length of hose 3500 metres long. Once it is all assembled and the team is ready to go, it will take them about 3 days to melt a 30 cm wide hole to the top of the lake.

Then they'll have just 24 hours to lower a probe (and another coring device for taking sediment samples) down the hole into the lake water and down about 100 metres to the lake bottom. The probe will sample the water as it descends and grab mud off the bottom in its search for extreme adapted microbes. It then has to be hauled back more than 3 kilometres up to our world before the shaft in the ice freezes up.

As for the Russian project, Lake Vostok is the size of Lake Ontario, 1000 metres deep and is under 4 km of ice. It's been isolated under ice for maybe 20 million years. The most interesting time-encapsuled life-forms are likely to be there. Last February the Russians had to stop 30 metres short of the lake top because of bad weather and drilling snags. Using a more standard drilling technique, the drilling gets trickier as you go deeper. Although the Russians may break through into Vostok's water this year, they won't retrieve any samples. According to their plan, they'll do that the following year and will only get a glimpse of life forms in the lake's upper reaches.
Producer: Andrew Luck-Baker.