Europa Vostok Initiative

[search]

Europa Vostok Initiative<br /><br />A NASA program of investigation of Lake Vostok with the ultimate goal of developing instrumented probes to explore the sub-ice oceans thought to exist on Jupiter's moons Europa and Callisto. Important preliminary data have been obtained from the Lo'ihi Underwater Volcanic Vent Mission Probe.<br /><br />Vostok, Lake<br /><br />An underground Antarctic lake near to the Russian Vostok Station, discovered in 1977 during an airborne radio-echo survey of ice depths over central East Antarctica. In 1993, altimetry measurements from the ERS-1 satellite verified the lake's existence and extent, confirming it to be by far the largest deep sub-ice body of water on the planet. In 1996, Russian and British scientists combined radio sounding, altimetric, and seismic data to provide the most comprehensive picture of the lake currently available.1 <br /><br />Lake Vostok extends over about 14,000 square km (roughly the size of Lake Ontario) and is overlaid by 3,710 m (12,170 ft.) of ice. It has a maximum depth of 510 m, an average depth of 125 m, a volume of 1800 cubic km, and a bed that is 710 m below sea level. It may be 500,000 to 1 million years old and, based on density measurements, is composed of fresh water. <br /><br />Researchers hope that, aside from its intrinsic interest, Lake Vostok will serve as a natural terrestrial laboratory to help understand the conditions that may exist in the putative subsurface oceans on Jupiter's moons Europa and Callisto. In particular, NASA has identified four objectives in its Europa Vostok Initiative. These are to investigate the nature and origin of the lake, obtain evidence of long-term climatic change associated with it, identify a site suitable for in-situ microbiological exploration, and validate the design of planetary radar sounders

 

[search]

Lake Vida<br /><br />A 5-km-long ice-sealed super-concentrated saltwater lake found under 19 m of ice in the region of Antarctica known as McMurdo Dry Valleys. Discovery of the all-year-round liquid nature of the lake was announced in December 2002 together with that of 2,800-year-old microbes, which had been revitalized after extraction from ice core samples above the lake. The water remains liquid because it is seven times saltier than seawater and so will not freeze even at -10°C – the temperature below the ice cover. Because the body of water has been isolated for thousands of years, it may represent a previously unknown type of ecosystem and serve as an important natural laboratory for researchers interested in looking for evidence of microbial life on other worlds, including Mars. Conceivably, a Lake Vida-type ecosystem served as the final niche for life on Mars before the surface water froze solid. If so, given that the organisms in the Vida samples managed to survive the low temperatures, lack of light, and hypersalinity (see halophiles) for millennia and to begin photosynthesising again when unfrozen, it is possible that the same revitalization could occur with microbes on Mars. Research at Lake Vida could help scientists find out more about possible life in Lake Vostok, the largest of over 70 sub-glacial lakes in Antarctica, which lies more than 4 km beneath the East Antarctic Ice Sheet.