ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Friday, March 7, 1997 TAG: 9703070028
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: ASSOCIATED PRESS
There's a chance -a very small chance - that robots probing Mars might bring back hostile life forms, researchers say.
It's come to this: A panel of scientists is warning NASA to be careful about contaminating Earth with hostile bugs when robots go to Mars to bring back soil samples. The risk is small, they say, but ``not zero.''
While researchers don't want to raise fears of an Andromeda Strain - as in Michael Crichton's best-selling novel about an extraterrestrial organism that threatens life on Earth - they urge that anything brought back be considered dangerous until proven otherwise.
``If life forms ever existed on Mars, either by having been formed in an independent origin or having been transferred there from Earth, it is possible that they have continued to exist up to the present time,'' said a National Research Council report released Thursday.
Two U.S. probes, the Mars Pathfinder and the Mars Global Surveyor, are en route to the Red Planet, but the first sample-return mission is not scheduled until the middle of the next decade.
To prepare for that, NASA asked the research council's Space Studies Board in 1995 for guidance about protecting Mars from our microbes - and us from Mars'. An engineer and a lawyer were on the panel with the scientists.
Even if Martian microorganisms were somehow introduced into Earth's environment, the study said, ``the likelihood that they could survive and grow and produce harmful effects is judged to be low.''
The Martian bugs ``would be unlikely to be able to compete successfully with Earth organisms, which are well adapted to their habitats.''
Some of the anxiety about contamination from another planet was fueled in August when NASA researchers announced they'd found possible signs of life in a meteorite discovered in Antarctica 13 years ago.
The rock, originating on Mars, contained chemicals that can be produced by bacteria and it had unusual microscopic shapes that could be interpreted as fossilized microbes.
Other researchers have disputed the interpretation by the NASA researchers, and their conclusions about Martian life remain controversial.
The National Research Council panel said that while the Martian surface is believed inhospitable to life as we know it, ``there remain plausible scenarios for extant [still existing] microbial life on Mars - for instance, in possible hydrothermal [hot water] oases or in subsurface regions.''
Therefore, the report said, samples returned from Mars should be ``treated as though potentially hazardous until proven otherwise.'' That includes sterilizing them in space or putting them in containers - and building a safe facility in which to check them out.
The recommendations are reminiscent of the precautions taken with the first three teams of astronauts that landed on the moon from 1969 to 1971. On Earth, their spacecraft was hosed down with antiseptics and the astronauts were kept in isolation for 21 days while doctors poked, probed and tested, looking for moon bugs. None was ever found.
Scientists believe that life on Earth first arose from a hot spring-like environment or that there were conditions such as heating of the oceans by an asteroid impact.
And on Mars? ``Given the extensive evidence for both heat sources and accessible water, it is likely that hydrothermal systems have been present throughout Martian history,'' the panel said.
Or, Earth itself might have put life on Mars through asteroid impacts that splattered Earth microbes into space.
``In summary,'' the report says. ``the surface of Mars is inhospitable to life as we know it, although there may be localized environments where life could exist.''
LENGTH: Medium: 73 linesby CNB