ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Friday, November 1, 1996 TAG: 9611010066
SECTION: NATIONAL/INTERNATIONAL PAGE: A7 EDITION: METRO
SOURCE: THE WASHINGTON POST
BRITISH SCIENTISTS have found new evidence that the Red Planet could have been lively just 600,000 years ago.
British scientists Thursday announced they had found strong new evidence that primitive life once existed on ancient Mars, along with tantalizing hints that similar organisms may even survive today.
The team of planetary geochemists analyzed two different meteorites that fell to Earth from Mars, including the same rock in which an American team last summer reported similar evidence, and a second sample billions of years younger.
The finding comes just as the American and Russian space agencies are preparing to launch a series of robot explorers to the fourth planet from the sun, where water once flowed. Scientists said the new evidence increases the odds that the robots will find signs of life.
The evidence in the second rock indicates life could have existed on Mars just 600,000 years ago. ``Geologically speaking, this is sufficiently recent for there to be a good chance that life might still exist in protected areas on our planetary neighbor,'' the team concluded in a report presented at a meeting in London at the Royal Society hosted by the British minister of science.
The new findings both corroborate and go beyond the earlier evidence, according to Michael Meyer, who heads NASA's exobiology program.
The British team reported the presence of organic compounds - complex organic molecules of the sort required for carbon-based life - in both Mars rocks. While the American team also found organic material, the British added a second configuration, or form, of it, scientists said.
Using a different technique from the American team, they also tied this material in some instances to a second line of evidence - the signature of ``microbially produced methane'' similar to that produced by bacteria that flourish in cows' stomachs and other places on Earth.
The new findings, based on the ratios of isotopes (varying atomic weights of the same chemical substance) in the meteorites' organic material, matched the ratios contained in some of the oldest fossils found on Earth, also of bacteria, according to the British team of Colin Pillinger, Ian Wright and Monica Grady of the Open University.
The news elated the American team that announced evidence of extraterrestrial life on Aug. 7, producing headlines around the world but also a barrage of skepticism.
``We are pleased that an international group of this stature has gone to work on the problem,'' said Everett Gibson Jr. of NASA's Johnson Space Flight Center, a leader of the U.S. team that also included David S. McKay of JSC and Richard N. Zare of Stanford University.
Gibson added that his group ``has taken a lot of heat'' as they expected, but ``we have a beautiful data set that will stand the test of time.'' In the workings of the scientific method, he said he believes it will take at least five years for the scientific community to reach a firm concensus on the issue of life on Mars.
LENGTH: Medium: 61 linesby CNB