What lies beneath? Antarctic mission to find life isolated deep under the ice

Extraordinary journey may reveal unknown life forms cut off from outside world – and pave a way to Jupiter

The mission will explore the world below the ice sheet (Bryan and Cherry Alexandet)

Twelve British scientists are about to embark on a gruelling expedition to the Antarctic, sleeping and living packed together in small tents for months on end, testing their endurance of the conditions – and one another – in a quest to uncover a lost world frozen beneath the ice for hundreds of thousands of years.

Their search for microbial lifeforms will take them to the darkest depths of an Antarctic lake that has been buried under three kilometres of ice.

The British team will later this year start to drill through the thick ice sheet of West Antarctica to retrieve samples of water and mud from Lake Ellsworth, one of about 150 subglacial lakes in the frozen continent.

The pioneering expedition, which is led by the British Antarctic Survey and is being closely monitored by Nasa as a template for a future space mission to an ice-bound moon of Jupiter, is one of the most ambitious attempts ever to find “extremophile” microbes living in the harshest conditions.

Scientists believe that if life does exist in the lake, it has been isolated for up to half a million years. Although no sunlight has ever penetrated the lake during this time, microbes could be living off other sources of chemical energy.

Lake Ellsworth exists because geothermal heat from the ground melts the underside of the ice sheet, leading to liquid water gathering in a subglacial valley the size of Lake Windermere, hermetically sealed from the atmosphere by the ice sheet sitting on top of it.

Planning the £8m mission has been a logistical and engineering nightmare, involving the transport of 100 tonnes of equipment to one of the remotest places on the planet where summer temperatures hover around -25C.

“This is an incredibly exciting and terrifying time for us. There is nothing small about what we are doing, the scale is phenomenal,” said Chris Hill, the mission’s programme manager.

“This time last year a small ‘advance party’ transported nearly 70 tonnes of equipment 16,000km from the UK to the drilling site. One year later, we will ship another 26 tonnes of equipment so we can complete stage two of this challenging field mission,” Mr Hill told the British Science Festival in Aberdeen. “We set foot on the ice again in October and hope to bring samples to the surface in December 2012.”

The team of 12 men consists of four scientists, five engineers, a programme manager, a camp manger (who does the cooking) and a cameraman to record everything for the media.

They will sleep in three four-man tents specially designed as “weather havens”. There will also be a living room tent for eating and cooking and an “office tent” at the drilling site.

Everything taken to the site will be shipped out again, even the human waste, to keep the area pristine. The men will have books, magazines, a DVD player and internet access to entertainment them for the two a half months of the exploration.

“Anyone with strength enough to go cross-country skiing will be able to do so, but to be honest most people at the end of the day are so exhausted they just want to eat and go to bed,” said Hill.

The team has been hand-picked and psychologically matched to make sure they get on with one another, but small arguments are almost inevitable, Mr Hill said. “Even the most good-natured person will throw their toys out of the pram because the conditions are so tough, But I feel we have a good mix of men and they should get along.”

The equipment is transported by sea and cargo plane, with the final leg of the journey over the ice made by a train of heavy snow tractors. Engineers are on schedule to begin erecting the drilling rig by the end of November and hope to drill down through the ice in the second week of December.

The water and mud samples will be brought to the surface and provisionally analysed on site, with the first scientific results coming just before Christmas, said Professor Martin Siegert of Bristol Univeristy, the mission’s principal investigator.

“If there is life in the lake we will know pretty much immediately and we will tell people about it. For the first time we are standing at the threshold of making new discoveries about a part of our planet that has never been explored in this way,” Professor Siegert said.

“Finding life in a lake that could have been isolated for up to half a million years is an exciting prospect.”

The drill consists of a high-pressure jet of water heated to 100C so that it melts its way through the ice. Once the drilling begins, the engineers cannot stop until the mission is complete as the empty borehole will freeze over after 24 hours, Professor Siegert said.

Enormous efforts have gone into sterilising the drilling equipment to prevent microbial contamination of the lake from the surface. Even the drilling water used in the high-pressure jet will be filtered to pharmaceutical standards before it is injected into the borehole, he said.

Once the drill has reached the lake, it will be pulled back up through the borehole to allow the scientific instruments to be lowered into the water. The first will consist of a five-metre long probe for sampling the lake, while the second instrument is a sediment corer for taking mud samples from the lake floor.

“The simple question we will be posing is: could life adapt to these extreme environments. It is only microbes that would have any chance of living in these extreme conditions,” said Professor John Purnell of Aberdeen University. “Finding evidence of such compounds would show us that if life can withstand even the deepest, darkest and most isolated conditions for more than a million years, then it has the ability to exist anywhere – and by that I mean not just on Earth.”