The initial
step for any exploration is the scouting expedition. We have all been taught
that in 1803 Meriwether Lewis and William Clark set out across the North
American continent to explore the uncharted West. They thought they might find
woolly mammoths, and hoped to find a water route across the vast continent. Instead
they found daunting mountain ranges, fascinating native cultures, and water
ranging in form from dramatic cascades to stagnant salt pools. Today's astrobiologists,
those intrepid modern day explorers investigating the possibilities for life in
the universe, are still following the water. One exemplar of this phenomenon is
Dr. Adrian Brown, a Carl Sagan Center geologist/astrobiologist and a native
Australian, who will lead a September scouting expedition of spectroscopists
through the Western Australian desert in search of dry acidic lakes and banded
iron deposits. You may ask, "What is the connection between dry lake beds
and following the water?" The answer is Mars.
When NASA's
"Mars Czar," G. Scott Hubbard, restructured the current robotic NASA
Mars Exploration Program, he dubbed the science strategy for the whole program "Follow
the Water." Since we know life occurs on earth wherever there is liquid
water (for even a part of the year), if you follow the water on other planets,
the path may lead you to life on those other worlds. So far, arguably, the
strategy has been very successful. The Mars Exploration Rovers are still exploring Mars, and
coupled with the latest high resolution images from the Mars Reconnaissance
Orbiter (MRO), are providing an increasingly corroborated story of water on
Mars both past and possibly even current. To increase our understanding of the
Mars data, we look to analogous places on earth. There we conduct parallel field
work similar to current Mars efforts, and by employing all the sophistication humans
and laboratory equipment can provide, vastly improve our understanding of the
Mars data. Western Australia is a great place to do that.
Dr. Brown
is a part of the team of scientists working on data from the Compact
Reconnaissance Imaging Spectrometer for Mars (CRISM)
mapping Mars from the MRO spacecraft. A marvelously versatile spectrometer in
operation since last November, CRISM has already returned a mountain of
intriguing data – more, thus far, than was returned in nine years of operations
by the Mars Global Surveyor, another great spacecraft. CRISM's data are showing
a far more complex geology and mineralogy than might have been anticipated and
much of it points to water. To increase their understanding of this rich data
set, Adrian and his colleagues here on Earth will eventually fly spectrometers
2 to 3 kilometers above targeted areas in Western Australia and explore the
same area from the ground with field spectrometers, hand lenses, portable
microscopes, computers and various other pieces of equipment to expand their
understanding of how the spectral images and data relate to actual ground
features. To prepare for the expedition, they have to do a scouting run.
The crucial
step in any scientific endeavor is to acquire funding. Dr. Brown joined a team
led by Dr. Simon Hook of JPL who successfully proposed the study as a larger interdisciplinary
exploration that will include forays into Brazil and Utah. Their funding agency
is NASA. Brown's international team will accomplish two field expeditions, one
ground scouting trip to pinpoint the most useful target areas, which is to be
followed by a second trip next year that will combine flights taking data from
the air with further ground research. The interlude between the two expeditions
will give them adequate time to study and correlate their data and then compare
it to the CRISM data to see what is most useful and how they might improve the
approach.
The team
arrives in Perth on September 5th, early spring down under, and has
until September 23rd to recover from jet lag. Then, with their
rented vehicles, they explore multiple sites at 3 field targets. To ensure that
all goes smoothly, Adrian is spending a fair chunk of his summer here at the
SETI Institute juggling airline schedules, renting the all-wheel-drive vehicles
that will carry them safely through the Australian outback, coordinating with
mining operations they might be visiting – much of their target area is heavily
involved in Australia's growing mining industry – finding motels that will
accommodate them during their travels, assembling information from drill core
libraries, and handling dozens of other details that will allow the team of
scientists to concentrate on science once they are on their way.
Like most
worthwhile endeavors, science is a far more complex business than might first appear,
once you peer deeply into the day-to-day working of any aspect of it. These
days, I think Dr. Brown is feeling more like a tour guide than a world-class
high resolution spectroscopist, and is called upon to manage a myriad of
details in areas that he might never have dreamed had any connection to
science. Still, once out in the field, he and his team will certainly learn
things that they couldn't have anticipated, and not just about Western Australia. Their efforts have the potential to significantly advance our understanding of
the CRISM data and Mars. By following the water – the traces and signatures it
leaves behind and the kind of morphologies that harbor those signatures –
Adrian Brown could acquire a critical piece of the puzzle that drives most astrobiologists.
There might no longer be "gold in them thar hills," but what if there's
life?
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