Ecosystem found under Antarctic ice sheet raises hopes for alien life
Tiny rock-eating lifeforms have been discovered living half a mile beneath pack ice in Antarctica, raising the prospect that life could exist in similarly hostile environments such as Mars
Ecosystems could be living in underground lakes and rivers throughout Antarctica Photo: Sergey Kokinskiy / Rex Features
By Sarah Knapton, Science Correspondent
7:04PM BST 20 Aug 2014
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An entire ecosystem has been discovered under the Antarctic, raising hopes that life could exist in extreme environments, such as other planets in the solar system.
Researchers have discovered that tiny life-forms are thriving in a lake under half a mile of pack ice, even though the habitat has not seen sunlight or fresh air for a million years.
The discovery has led to excitement among the scientific community who had previously theorised that microorganisms may be able to survive by evolving novel ways to generate energy.
And it raises the possibility that similar life could exist on Mars or other icy planets or moons.
“It's the first definitive evidence that there's not only life, but active ecosystems underneath the Antarctic ice sheet, something that we have been guessing about for decades,” said lead researcher Brent Christner, Professor of Biology at Louisiana State University in the US.
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“We are looking at a water column that probably has about 4,000 things we call species. It's incredibly diverse.
“I think that this does nothing but strengthen the case for life on other icy bodies in solar system and beyond.
“The first time we went to Antarctica and the first place we selected to drill a hole we found life. So it’s not much of a stretch that in similar conditions, like on the icy moon of Jupiter, Europa, life could exist there.”
One of the microogranisms under the microscope Credit: Trista Vick-Majors
The microogranisms were found in Lake Whillans, a subglacial body of water beneath the Antarctic ice sheet on the southeastern edge of the Ross Ice Shelf in the west of the continent.
Similar microbes can be found in the deep oceans, but they rely on the remains of surface organisms, raining down from above, as energy sources.
In contrast, the environment under the glacier is so hostile that these new organisms are forced to ‘eat rock’, attaching themselves to mineral particles and harvesting tiny amounts of ammonium and nitrogen.
The Antarctic Ice Sheet covers an area one and a half times the size of the United States and contains 70 percent of Earth's freshwater.
More than 400 subglacial lakes and numerous rivers and streams are thought to exist beneath the Antarctic ice sheet, so such ecosystems may be widespread, researchers believe.
They say it proves that glaciers and ice-sheet beds are not sterile, but host diverse microbial communities.
“The team has opened a tantalizing window on microbial communities in the bed of the West Antarctic Ice Sheet,” said Prof Martyn Tranter, of the School of Geographical Sciences, at the University of Bristol.
“The findings even beg the question of whether microbes could eat rock beneath ice sheets on extraterrestrial bodies such as Mars. This idea has more traction now.”
The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project drilled down through half a mile of ice to reach the lake in January 2013 and took samples.
They discovered that the microorganisms were alive and growing. DNA tests proved they had not accidentally been brought in on equipment.
Professor John Priscu of Montana State University predicted more than a decade ago that life could exist under Antarctic ice.
"We were able to prove unequivocally to the world that Antarctica is not a dead continent," said Professor Priscu.
Doctoral researcher Trista Vick-Majors said she saw microscopic life moving under the microscope within hours of water being pulled out of the lake.
"It was very exciting. It will be hard to top," she said.
Researcher Alex Michaud added, "Some of the graduate students joke, 'How do we top this?' We can't."
The research was published in the journal Nature.
