Life Detection Instrument Passes Key Test on Road to Mars

http://www.berkeley.edu/news/media/r...8_moaucb.shtml

UC Berkeley Press Release

Life detection instrument passes key test on road to Mars
By Robert Sanders, Media Relations
28 June 2005

BERKELEY - The dry, dusty, treeless expanse of Chile's Atacama Desert
is
the most lifeless spot on the face of the Earth, and that's why Alison
Skelley and Richard Mathies joined a team of NASA scientists there
earlier this month.

The University of California, Berkeley, scientists knew that if the
Mars
Organic Analyzer (MOA) they'd built could detect life in that crusty,
arid land, then it would have a good chance some day of detecting life
on the planet Mars.

In a place that hadn't seen a blade of grass or a bug for ages, and
contending with dust and temperature extremes that left her either
freezing or sweating, Skelley ran 340 tests that proved the instrument
could unambiguously detect amino acids, the building blocks of
proteins.
More importantly, she and Mathies were able to detect the preference of
Earth's amino acids for left-handedness over right-handedness. This
"homochirality" is a hallmark of life that Mathies thinks is a critical
test that must be done on Mars.

"We feel that measuring homochirality - a prevalence of one type of
handedness over another - would be absolute proof of life," said
Mathies, professor of chemistry at UC Berkeley and Skelley's research
advisor. "We've shown on Earth, in the most Mars-like environment
available, that this instrument is a thousand times better at detecting
biomarkers than any instrument put on Mars before."

The instrument has been chosen to fly aboard the European Space
Agency's
ExoMars mission, now scheduled to launch in 2011. The MOA will be
integrated with the Mars Organic Detector, which is being assembled by
scientists directed by Frank Grunthaner at the Jet Propulsion
Laboratory
(JPL) in Pasadena together with Jeff Bada's group at UC San Diego's
Scripps Institution of Oceanography.

Skelley, a graduate student who has been working on amino acid
detection
with Mathies for five years and on the portable MOA analyzer for the
past two years, is hoping to remain with the project as it goes through
miniaturization and improvements at JPL over the next seven years in
preparation for its long-range mission. In fact, she and Mathies hope
she's the one looking at MOA data when it's finally radioed back from
the Red Planet.

"When I first started this project, I had seen photos of the Martian
surface and possible signs of water, but the existence of liquid water
was speculative, and people thought I was crazy to be working on an
experiment to detect life on Mars," Skelley said. "I feel vindicated
now, thanks to the work of NASA and others that shows there used to
berunning liquid water on the surface of Mars."

"The connection between water and life has been made very strongly, and
we think there is a good chance there is or was some life form on
Mars,"
Mathies said. "Thanks to Alison's work, we're now in the right position
at the right time to do the right experiment to find life on Mars."

Mathies said that his experiment is the only one proposed for ExoMars
or
the United States' own Mars mission - NASA's roving, robotic Mars
Science Laboratory mission - that could unambiguously find signs of
life. The experiment uses state-of-the-art capillary electrophoresis
arrays, novel micro-valve systems and portable instrument designs
pioneered in Mathies' lab to look for homochirality in amino acids.
These microarrays with microfluidic channels are 100 to 1,000 times
more
sensitive for amino acid detection than the original life detection
instrument flown on the Viking Landers in the 1970s.

The Atacama Desert was selected by NASA scientists as one of the key
spots to test instruments destined for Mars, primarily because of its
oxidizing, acidic soil, which is similar to the rusty red oxidized iron
surface of Mars. Skelley and colleagues Pascale Ehrenfreund, professor
of astrochemistry at Leiden University in The Netherlands, and JPL
scientist Frank Grunthaner visited the desert last year, but were not
able to test the complete, integrated analyzer.

This year, Skelley, Mathies and other team members carried the complete
analyzers in three large cases to Chile by plane - in itself a test of
the ruggedness of the equipment - and trucked them to the barren Yunguy
field station, essentially a ramshackle building at a deserted
crossroads. With a noisy Honda generator providing power, they set up
their experiments and, with six other colleagues, tested the integrated
subcritical water extractor together with the MOA on samples from
popular test sites such as the "Rock Garden" and the "Soil Pit."

One thing they learned is that with low environmental levels of organic
compounds, as is likely to be the case on Mars, the microfluidic
channels in the capillary disks don't get clogged as readily as they do
when used to test samples in Berkeley with its high bioorganic levels.
That means they'll need fewer channels on the instrument that travels
to
Mars, and the scanner used to read out the data needn't be as
elaborate.
This translates into a cheaper and easier way to build instruments, but
more importantly, an instrument that is smaller and uses less power.

With the success of this crucial field test, Skelley and Mathies are
eager to get to work on a prototype of their instrument that would fit
in the allowed space within the ExoMars spacecraft.

"I'm much more optimistic that we could detect life on Mars, if it's
there," Mathies said.