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This research shows Lake Vostok to have high levels of oxygen. It had
been thought that Lake Vostok would have low levels of oxygen because most oxygen in bodies of water comes from diffusion from the atmosphere, and this mechanism would not be available for the permanently ice-covered lake. For this reason most scientists thought there could not be advanced life that could exist there. A similar argument had been made towards the Jovian moon Europa. However, this new research leaves open the possibility advanced life could exist in Lake Vostok and therefore might possibly also exist on Europa. I discussed some possibilities for how advanced life might exist on Europa in a prior sci.astro post: From: Robert Clark ) Subject: Possibilities for complex life on Europa. Newsgroups: sci.astro, sci.bio.misc, alt.sci.planetary Date: 2001-01-27 19:42:02 PST Bob Clark 2010: Odyssey Two by Arthur C. Clarke 11. Ice and Vacuum, p. 74 'Who is it?' whispered someone, to a chorus of shushes. Floyd raised his hands in a gesture of ignorance - and, he hoped, innocence. '... know you are aboard Leonov... may not have much time... aiming my suit antenna where I think...' The signal vanished for agonizing seconds, then came back much clearer, though not appreciably louder. '... relay this information to Earth. Tsien destroyed three hours ago. I'm only survivor. Using my suit radio - no idea if it has enough range, but it's the only chance. Please listen carefully. THERE IS LIFE ON EUROPA. I repeat: THERE IS LIFE ON EUROPA.' The signal faded again. A stunned silence followed that no one attempted to interrupt. While he was waiting, Floyd searched his memory furiously. He could riot recognize the voice - it might have been that of any Western-educated Chinese. Probably it was someone he had met at a scientific conference, but unless the speaker identified himself he would never know. '... soon after local midnight. We were pumping steadily and the tanks were almost half full. Dr Lee and I went out to check the pipe insulation. Tsien stands - stood - about thirty metres from the edge of the Grand Canal. Pipes go directly from it and down through the ice. Very thin - not safe to walk on. The warm upwelling...' Again a long silence. Floyd wondered if the speaker was moving, and had been momentarily cut off by some obstruction. '... no problem - five kilowatts of lighting strung up on the ship. Like a Christmas tree - beautiful, shining right through the ice. Glorious colours. Lee saw it first - a huge dark mass rising up from the depths. At first we thought it was a school of fish - too large for a single organism - then it started to break through the ice..." http://www.amazon.com/exec/obidos/tg...831820-4340819 Andrew Yee wrote in message ... Kathleen Burton NASA Ames Research Center, Moffett Field, Calif. August 11, 2003 Phone: 650/604-1731 or 604-9000 Email: RELEASE: 03-57AR RESEARCHERS FIND ANTARCTIC LAKE WATER WILL FIZZ LIKE A SODA Water released from Lake Vostok, deep beneath the south polar ice sheet, could gush like a popped can of soda if not contained, opening the lake to possible contamination and posing a potential health hazard to NASA and university researchers. A team of scientists that recently investigated the levels of dissolved gases in the remote Antarctic lake found the concentrations of gas in the lake water were much higher than expected, measuring 2.65 quarts (2.5 liters) of nitrogen and oxygen per 2.2 pounds (1 kilogram) of water. According to scientists, this high ratio of gases trapped under the ice will cause a gas-driven "fizz" when the water is released. "Our research suggests that U.S. and Russian teams studying the lake should be careful when drilling because high gas concentrations could make the water unstable and potentially dangerous," said Dr. Chris McKay of NASA's Ames Research Center in California's Silicon Valley. McKay is lead author of a paper on the topic published in the July issue of the 'Geophysical Research Letters' journal. "We need to consider the implications of the supercharged water very carefully before we enter this lake," said Dr. Peter Doran, a co-author and associate professor of Earth and Environmental Sciences at the University of Illinois at Chicago. Lake Vostok is a rich research site for astrobiologists, because it is thought to contain microorganisms living under its thick ice cover, an environment that may be analogous to Jupiter's moon, Europa. Europa contains vast oceans trapped under a thick layer of ice. Russian teams are planning to drill into Lake Vostok's 2.48 mile (four kilometer) ice cover in the near future, and an international plan calls for sample return in less than a decade. An important implication of this finding is that scientists expect oxygen levels in the lake water to be 50 times higher than the oxygen levels in ordinary freshwater lakes on Earth. "Lake Vostok is an extreme environment, one that is supersaturated with oxygen," noted McKay. "No other natural lake environment on Earth has this much oxygen." The research also suggests that organisms living in Lake Vostok may have had to evolve special adaptions, such as high concentrations of protective enzymes, in order to survive the lake's oxygen-rich environment, the researchers say. Such defense mechanisms may also protect life in Lake Vostok from oxygen radicals, the dangerous byproducts of oxygen breakdown that cause cell and DNA damage. This process may be similar to that of organisms that scientists theorize may once have lived on Europa, whose ice layer and atmosphere are thought to contain radiation-produced radicals and oxygen. "We expect to find that the organisms in Lake Vostok are capable of overcoming very high oxygen stress," said co-author Dr. John Priscu, a geo-biologist at Montana State University in Bozeman. Priscu heads an international group of researchers that will deploy a remote observatory at Lake Vostok within three years and return samples within 10 years. The team also determined the ratios of gases in the lake. The scientists discovered that the air-gas mixture there, besides dissolving in the water, also is trapped in a type of structure called a 'clathrate'. In clathrate structures, gases are enclosed in an icy cage and look like packed snow. These structures form at the high pressure depths of Lake Vostok and would be unstable if brought to the surface. Lake Vostok is located 2.48 miles (four kilometers) beneath the East Antarctic Ice Sheet. The lake, and more than 70 other lakes deep beneath the polar plateau, are part of a large, sub-glacial environment that has been isolated from the atmosphere since Antarctica became covered with ice more than 15 million years ago. Scientists theorize that Lake Vostok probably existed before Antarctica became ice covered, and may contain evidence of conditions on the continent when the local climate was subtropical. For images and further information about plans to return research samples from Lake Vostok, go to: http://salegos-scar.montana.edu/ The paper's authors also include K.P. Hand, Stanford University and Dr. D.T. Andersen, the SETI Institute. The research was jointly funded by NASA and the National Science Foundation. |
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On Mon, 11 Aug 2003 15:34:22 -0400, Andrew Yee wrote:
Kathleen Burton NASA Ames Research Center, Moffett Field, Calif. August 11, 2003 Phone: 650/604-1731 or 604-9000 Email: RELEASE: 03-57AR RESEARCHERS FIND ANTARCTIC LAKE WATER WILL FIZZ LIKE A SODA [. . .] A team of scientists that recently investigated the levels of dissolved gases in the remote Antarctic lake found the concentrations of gas in the lake water were much higher than expected, measuring 2.65 quarts (2.5 liters) of nitrogen and oxygen per 2.2 pounds (1 kilogram) of water. According to scientists, this high ratio of gases trapped under the ice will cause a gas-driven "fizz" when the water is released. [. . .] Strange. Wonder if this results from gas being delivered by bubbles trapped in the glacial ice to the ceiling of the lake, which then dissolve when the ice melts on the upstream end of the ceiling. The pressure required to drive atmospheric gases into clathrates on the downstream end of the ceiling would be much higher than atmospheric. Note that since high oxygen concentrations were found, microbial activity and geological supply of reducing substances to the lake must be less than the rate of delivery of oxygen through the ice. One question: I had not heard of a drilling breakthrough up to this point -- does this measurement mean that someone finally stuck a drill bit through, or are these measurements of ice from the downstream end of the lake ceiling? -- Lucius Chiaraviglio Approximate E-mail address: To get the exact address: ^^^ ^replace this with 'r' ||| replace this with single digit meaning the same thing (Spambots of Doom, take that!). |
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