LOS ANGELES (AP) — The Phoenix lander's first chemical sniff
of Martian soil did not turn up any trace of the building blocks of life. Its
next whiff could be its last.
Engineers said a short circuit that occurred last month in
one of its test ovens designed to shake and bake minuscule
soil samples could happen again when the instrument is turned on.
"Since there is no way to assess the probability of
another short circuit occurring, we are taking the most conservative approach
and treating the next sample ... as possibly our last," the NASA mission's
chief scientist, Peter Smith of the University of Arizona in Tucson, said in a
statement Wednesday.
Phoenix, which landed
near the Martian north pole on May 25, has eight single-use ovens that heat
and analyze Martian soil and ice for signs of organic, or carbon-based,
compounds that are essential for life.
The lander
delivered its first soil sample scooped up from the surface to one of its ovens
last month. The experiment did not yield any ice or organics. Initially, the
clumpy dirt could not fit through the oven's opening so scientists vibrated the
instrument several days to break it up. Engineers think the short circuit
occurred as a result of the repeated shakes.
Scientists want to bake another soil sample mixed with icy
bits in another oven next week. Since this could be the last time researchers
conduct this experiment, they planned extensive testing on Earth to make sure
they can quickly get the icy soil into the oven before the ice evaporates.
Meanwhile, Phoenix's robotic arm was set to sprinkle soil
particles taken from a trench dubbed Snow White onto its microscope on Thursday
for analysis. If there are leftovers, the rest will be dumped into its wet
chemistry lab.
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