http://news.discovery.com/space/lake-vostok-aliens-121602.html
Alien Life Clues in Antarctic Ice? |
February 16, 2012 5:30:00 AM
When a Russian team broke through 12,365 feet of solid Antarctic ice last week to reach an ancient buried freshwater lake, scientists eager to fill some gaps in Earth's history were overjoyed. But they weren't the only ones.
Seeing parallels between Antarctica's subterranean Lake Vostok and suspected oceans beneath the ice-crusted moons of Jupiter and Saturn, scientists searching for life beyond Earth are eagerly following the Russian project.
They don't expect water samples from Lake Vostok will hold alien life, though any life it contains may have taken a slightly different evolutionary path than what appears on the planet today. That's because Lake Vostok, the deepest and most isolated of Antarctica's subglacial lakes, has been cut off from the atmosphere for at least 14 million years.
The lakes, which were discovered via satellite imagery in the late 1990s, owe their existence to the thick Antarctic ice, which acts like a blanket to trap heat coming from inside Earth, keeping water liquid.
"If they find evidence of life there -- and I do think Lake Vostok has life in it -- it's going to be Earth-like," astrobiologist Dale Andersen, with the SETI Institute's Carl Sagan Center for the Study of Life in the Universe, told Discovery News.
"It's going to be the same kind of life you find everywhere else. It may be that life has evolved differently, but it's still Earth-like, still based on the same DNA structure," Andersen said.
"The real value is that it helps us learn how to explore these kinds of environments better. It opens up your imagination for how to explore these kinds of environments, whether it's on Earth or Europa," he said.
Scientists suspect Lake Vostok's water is about 1 million years old and is supersaturated with oxygen and other gases, a difficult place for life to exist. Some life that might be there are bacteria and single-celled microorganisms called archea.
It would be surprising if Lake Vostok had no life, NASA astrobiologist Chris McKay told Discovery News.
"The ice above the lake is known to contain low levels of viable but dormant organisms frozen into the ice. As this ice melts into Lake Vostok, it will carry these microorganisms so Lake Vostok is not likely to be sterile," he said.
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"Sterile is not the same as habitable," he added. "It may be that the environment in the lake does not provide an energy source or nutrients for life. Thus, there may be life there carried in with the melting ice, but there would not be an ecology."
Lake Vostok may offer lessons on how life spreads and how to find habitable environments. The project also should help scientists and engineers designing equipment to look for life beyond Earth and processes to make sure anything found is not the result of contamination.
Whatever secrets Lake Vostok holds are safe for at least another year. Russia won't be able to retrieve its water sample until the next Antarctic summer. By that time, teams of British and American scientists may have had time to retrieve and analyze samples from two other shallower sub-glacial lakes.
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