www.space.com/scienceastronomy/mars_life_050216.html
This perspective image, taken by the High Resolution Stereo Camera (HRSC) on board ESAs Mars Express spacecraft, shows the central part of the 40 00-kilometre long Valles Marineris canyon on Mars. The HRSC obtained thi s image during during orbits 334 and 360, on 24 April and 2 May 2004 res pectively, with a resolution of approximately 21 metres per pixel for th e earlier orbit and 30 metres per pixel for the latter.
Brian Berger Space News Staff Writer posted: 16 February 2005 02:09 pm ET WASHINGTON -- A pair of NASA scientists told a group of space officials a t a private meeting here Sunday that they have found strong evidence tha t life may exist today on Mars, hidden away in caves and sustained by po ckets of water. The scientists, Carol Stoker and Larry Lemke of NASAs Ames Research Cente r in Silicon Valley, told the group that they have submitted their findi ngs to the journal Nature for publication in May, and their paper curren tly is being peer reviewed. What Stoker and Lemke have found, according to several attendees of the p rivate meeting, is not direct proof of life on Mars, but methane signatu res and other signs of possible biological activity remarkably similar t o those recently discovered in caves here on Earth. Stoker and other researchers have long theorized that the Martian subsurf ace could harbor biological organisms that have developed unusual strate gies for existing in extreme environments.
search for subsurface life near the Rio Tinto riverso-called becaus e of its reddish tintthe product of iron being dissolved in its highly a cidic water. Stoker did not respond to messages left Tuesday on her voice mail at Ames .
com in 2003, weeks before leading the expedition to southwestern Spain, that by studying the very acidic Rio Tinto, she and other scientists hoped to characterize the potential for a chemical bio reactor in the subsurface an underground microbial ecosystem of sorts th at might well control the chemistry of the surface environment. Making such a discovery at Rio Tinto, Stoker said in 2003, would mean unc overing a new, previously uncharacterized metabolic strategy for living in the subsurface. For that reason, the search for life in the Rio Tinto is a good analog for searching for life on Mars, she said. Stoker told her private audience Sunday evening that by comparing discove ries made at Rio Tinto with data collected by ground-based telescopes an d orbiting spacecraft, including the European Space Agencys Mars Express , she and Lemke have made a very a strong case that life exists below Ma rs surface.
methane signatures that could be a sign of an active underground biosphere and nearby surface concentrat ions of the sulfate jarosite, a mineral salt found on Earth in hot sprin gs and other acidic bodies of water like Rio Tinto that have been found to harbor life despite their inhospitable environments.
bolstered the case for water on Mars when it discovered jarosite and other mineral salts o n a rocky outcropping in Merdiani Planum, the intrepid rovers landing si te chosen because scientists believe the area was once covered by salty sea.
NASA has no firm plans for sending a drill-equipped lander to Mars, but t he agency is planning to launch a powerful new rover in 2009 that could help shed additional light on Stoker and Lemkes intriguing findings. Dub bed the Mars Science Laboratory, the nuclear-powered rover will range fa rther than any of its predecessors and will be carrying an advanced mass spectrometer to sniff out methane with greater sensitivity than any ins trument flown to date. In 1996 a team of NASA and Stanford University researchers created a stir when they published findings that meteorites recovered from the Allen H ills region of Antarctica contained evidence of possible past life on Ma rs. Those findings remain controversial, with many researchers unconvinc ed that those meteorites held even possible evidence that very primitive microbial life had once existed on Mars.
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