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“Curiosity now has the chance, for example, to do
some closer up, but still remote, measurements,
using the ChemCam instrument with lasers, to
look at composition. I understand there is increasing pressure from the science side to allow that,
given this new discovery.”
BREAKING NEWS:
WATER ON MARS
NASA faces contamination dilemma over future investigations.
Curiosity rover already on red planet cannot study streaks left by
flowing water because it could be carrying bugs from Earth.
Nasa scientists may still be celebrating their
discovery of liquid water on Mars, but they
now face some serious questions about how
they can investigate further and look for signs
of life on the red planet.
The problem is how to find life without contaminating the planet with bugs from Earth.
Researchers at the space agency are keen for
the Curiosity rover to take a closer look at the
long dark streaks created by liquid water running down craters and canyon walls during the
summer months on Mars.
But the rover is not sterile and risks contaminating the wet areas with earthly bugs that will
have hitched a ride to the planet and may still
be alive.
The vehicle has been trundling around the
large Gale crater looking for evidence that
Mars was habitable in the ancient past. It has
so far uncovered evidence of past river networks and age-old lakes.
However, the dark, damp streaks, called recurring slope lineae (RSL), are a different prospect. Because they are wet at least part of the
time, they will be designated as special regions
where only sterile landers can visit. But such
a restriction could hamper scientists’ hopes of
looking for current life on Mars.
“There will
be heated
discussions
in the next
weeks and
months
about what
Curiosity
will be allowed to do
and whether it can go
anywhere near the RSLs”
said Andrew Coates of University College London’s Mullard space science laboratory.
An organisation called the committee on space research (Cospar)
draws up the rules on what
is called planetary protection, which exist to prevent
missions from Earth contaminating the pristine environments of other worlds.
Landers that are searching for
life must be exceptionally clean,
and fall under category IVb, but
those entering special regions are category IVc missions and must be cleaner still.
Curiosity was designed for category
IVb, and under Cospar rules is not allowed to enter areas where water
might be flowing. But that might
be up for discussion. Nasa’s Jim
Green argues that the intense
radiation environment on
Mars, in particular the ultraviolet light, might have
killed any bugs Curiosity carried into space, and so may be
clean enough to move into the
sites.
A recent report from the US National
Academy of Sciences and the European Science
Foundation, however, suggests that UV
light might not do the job, and could
make matters worse. “Although the
flux of ultraviolet radiation within
the Martian atmosphere would
be deleterious to most airborne
microbes and spores, dust
could attenuate this radiation
and enhance microbial viability,” the report states.
Curiosi H