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原文标题： NASA Researchers Claim Evidence of Present Life on Mars

WASHINGTON -- A pair of NASA scientists told a group of space officials at a private meeting here Sunday that they have found strong evidence that life may exist today on Mars, hidden away in caves and sustained by pockets of water.

The scientists, Carol Stoker and Larry Lemke of NASA’s Ames Research Center in Silicon Valley, told the group that they have submitted their findings to the journal Nature for publication in May, and their paper currently is being peer reviewed.

Stoker and other researchers have long theorized that the Martian subsurface could harbor biological organisms that have developed unusual strategies for existing in extreme environments. That suspicion led Stoker and a team of U.S. and Spanish researchers in 2003 to southwestern Spain to search for subsurface life near the Rio Tinto river—so-called because of its reddish tint—the product of iron being dissolved in its highly acidic water.

Stoker told SPACE.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 bioreactor in the subsurface - an underground microbial ecosystem of sorts that might well control the chemistry of the surface environment.

NASA has no firm plans for sending a drill-equipped lander to Mars, but the agency is planning to launch a powerful new rover in 2009 that could help shed additional light on Stoker and Lemke’s intriguing findings. Dubbed the Mars Science Laboratory, the nuclear-powered rover will range farther than any of its predecessors and will be carrying an advanced mass spectrometer to sniff out methane with greater sensitivity than any instrument 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 Hills region of Antarctica contained evidence of possible past life on Mars. Those findings remain controversial, with many researchers unconvinced that those meteorites held even possible evidence that very primitive microbial life had once existed on Mars.