ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Wednesday, August 7, 1996 TAG: 9608070056
SECTION: NATIONAL/INTERNATIONAL PAGE: A1 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: ASSOCIATED PRESS
note: below
A meteorite from Mars provides ``unequivocal'' evidence that life once existed on the red planet, scientists familiar with the discovery asserted Tuesday.
Researchers examining the rock from space recovered in Antarctica say it bears organic compounds that are unmistakable signs of life.
NASA officials in Washington and at the Johnson Space Center in Texas confirmed the report that research sponsored by the center had concluded the meteorite bore chemical evidence of past biological activity on Mars. But they declined to give further details.
A spokeswoman at the journal Science confirmed that a Mars paper had been received, but she said it would not be published until next week.
Meanwhile, word of the discovery flashed through the astronomy community.
One scientist familiar with the study, commenting only on condition of anonymity, said, ``The finding was unequivocal. This could be one of the biggest discoveries ever.''
Another scientist, also speaking only anonymously, said he was skeptical but if the report could be confirmed it would be a major discovery.
Past or present existence of life on Mars has been considered a possibility ever since studies by spacecraft landers showed that water was once present on the planet surface.
None of the Martian landers, however, found evidence that life now exists on Mars, nor did the robot craft find chemical markers for life in limited soil samples that have been analyzed.
The new findings center on a meteorite called Allan Hills 84001, the oldest of 12 pieces of rock that earlier studies confirmed as originating from Mars. It is thought the rocks were jolted away from Mars by some massive collision in ancient times and then drifted in space until they fell to Earth.
Allan Hills 84001 was found to have crystallized about 4.5 billion years ago, during the formation of the solar system. It is thought to have been knocked from the Martian surface about 15 million years ago and then to have smashed into the icy surface of Antarctica about 13,000 years ago.
The meteorite was discovered in 1984 and later identified as originating from Mars.
Scientists from NASA's Johnson Space Center, from Stanford University, the University of Georgia and from McGill University in Montreal, recently studied thin slices of the rock and found organic molecules called polycyclic aromatic hydrocarbons, or PAHs.
PAHs can be formed only in two ways - by biological action, such as by microorganisms, or in the process that forms planets.
However, the researchers determined that the PAHs in the rock were deposited in cracks that occurred after the meteorite was formed, suggesting the molecules were deposited by later biological activity.
Also, a scientist familiar with the find said that within the PAHs were particles of magnetite that are structurally like those made by bacteria on Earth. The researchers also found iron sulfide, a chemical compound related to bacterial action.
LENGTH: Medium: 64 lines ILLUSTRATION: PHOTO: File/1990 A meteorite from Mars provides "unequivocal"by CNBevidence of past life. color