The scientific desire to search for life on Mars is coming into
conflict with the need to prevent any such life from
endangering the astronauts or the Earth. The National
Research Council (NRC) is recommending that safety take
precedence over research and that missions to Mars should
try to avoid encountering any possible life forms there. The
NRC is part of the National Academy of Sciences, an
independent agency chartered by Congress to provide advice
to the government on scientific issues.
"While the threat to Earth's ecosystem from the release of
Martian biological agents is very low, the risk of harmful
effects is not zero and cannot be ignored," the council says.
The NRC has urged NASA to establish "zones of minimal
biological risk" by sending automated probes to test for
organic chemicals or other life forms. Astronauts would then
be sent to the areas with the lowest possibility of
encountering life.
Mars is known to once have had a lot of water on its surface,
making it a prime candidate for life forms such as bacteria,
which many scientists believe could still exist in the Martian
soil. A Mars landing craft would become coated with dust,
and astronauts walking on the planet to do scientific work
would bring some dust back inside with them, as happened
on the trips to the moon. To prevent a return of this material
to Earth, the NRC suggests a transfer in space where the
returning craft is docked to another vehicle and the
astronauts are transferred in a sterile atmosphere. The
original spacecraft would then be abandoned in space.
NASA "might be faced with requiring quarantine and
surveillance of returning astronauts until it is determined
that a threat no longer exists."
The NRC also recommends that NASA should determine the
size, shape and abrasiveness of the rocks at potential
landing sites. An unmanned Mars lander needs to study the
adhesiveness of the dust and the potential radiation
exposure at planned landing areas. A particular concern is
hexavalent chromium, a rare material on Earth which,
studies suggest, may be present in larger amounts on Mars.
The question the taxpayers who fund NASA might ask is
this: Why go to Mars if we don?t look for life there?
To see photos of possible life on Mars, read ?Dark Matter,
Missing Planets and New Comets? by Tom Van Flandern,
click here.
For more information, click here.
