An international team of scientists plumbing the bubblingblack depths of a geothermal hot spring in usahave discovered an unique community of microbes that thrive without sunlight or oxygen. The one-celled organismsknown as Archaeagrow by consuming hydrogen that is produced by hot water reacting with bedrock. The creatures produce tiny amounts of methane as a byproduct of their weird metabolism. This community is unlike anything else surviving on the Earth as most life on the planet flourishes not only in the presence of waterbut also relies on oxygensunlight and organic carbon (www.msnbc.comFebruary 242002

Astrobiologists say that these microbes closely resemble what they imagine might be lurking beneath the drybarren surface of Mars or the thick glaciers of Europaone of Jupiter's moons. In wake of the findingsresearchers said the question should no longer be whether extreme life exists on Mars or elsewhere. "Ratherdid life originate thereor was it transplanted from Earth?' asked Bruce Jakoskya planetary scientist at the University of Coloradousa .

Microbes like these have been the subject of speculation for 30 years. But finding them was another matter. Just for this studya team of seven government and university scientists spent more than a decade looking for promising locations. The research team surveyed the volcanically active Yellowstone region spread over Idaho and Montana states. The region is home to 80 per cent of the world's geysers and half of its geothermal features.

The researchers were looking for a subterranean environment that had water but no sunlightoxygen or organic carbon. They zeroed in on the Lidy hot springs near the Idaho-Montana line. Then they sank specially designed instruments down into the springs and collected the microbes with the help of filters.