Scientists
are busy at work "sample harvesting"--extracting comet particles from
aerogel-laden capture trays brought back to Earth last month via the Stardust
return capsule.
"The
pace of sample processing...removing and preparing the particles from the aerogel
cells...has ramped up considerably," said Peter Tsou, Stardust Deputy Principal
Investigator at the Jet Propulsion Laboratory in a recent update.
Detailed
scientific scrutiny of material captured during a flyby of Comet Wild 2 during
Stardust's nearly seven-year long collection route through space is now
underway. The craft's sample return capsule softly touched down January 15
within the remote desert landscape of the Utah Test and Training Range.
Once
recovered, the capsule was opened and the collected samples were transferred
over to NASA's Johnson Space Center (JSC) in Houston, Texas.
"The
first few Stardust samples have been removed from the comet tray and are
currently being analyzed by members of the science team," said Carlton Allen,
astromaterials curator at JSC. "Most of the aerogel cells remain intact in the
tray, and these are being carefully documented in the Stardust lab at Johnson Space Center," Allen told SPACE.com.
The
science team anticipates announcing initial results at the Lunar and Planetary
Science Conference, to be held in Houston March 13-17, Allen said.
Cosmic crud
Meanwhile,
some
150 eager scientists form an international team now ready for action. They will
dive into the dust particles collected by Stardust making use of a variety of
scientific devices.
The
Stardust spacecraft used a tennis racquet-shaped collector loaded with aerogel
to stop, quite literally, the speeding particles in their tracks. Incoming
comet particles made carrot-shaped tunnels in the aerogel as they stopped. At
the pointed tip of each tunnel a tiny particle can be found.
One
scientific team that has begun their study of extracted particles from Stardust
is at the Lawrence Livermore National Laboratory in Livermore, California.
There,
a research team has started dissecting the dust particles using powerful tools.
The analysis is a very detailed and precise exercise in which some tracks are
carved out of the aerogel with ultrasonic diamond blades. Scientists then use
microscopic needles to extract the dust from the tracks.
"It
is dirt," said John Bradley, director of the Lawrence Livermore National
Laboratory's Institute for Geophysics and Planetary Physics. "Basically, it's
cosmic crud," he commented in a press statement.
Small amount...big payoff
Stardust
returned less than a milligram of material--a small amount in quantity but sure
to result in a big payoff, researchers believe.
Bradley
likened the inspection of the tiny particles as "not unlike a colonoscopy with
the tracks."
The
actual tracks of cometary dust within the aerogel are visible to the naked eye,
and the particles themselves can be seen as white specks under a microscope.
"It's
unbelievable. It's almost surreal," Bradley explained. "We've collected so much
stuff. We can see it. With a needle and a spatula...I could put it on the tip of
my fingernail."
Arduous task
Dealing
with the ultra-small particles brought back by Stardust means utilizing highly
sophisticated equipment.
For
example, Livermore researchers are using a transmission electron microscope--the
world's most powerful electron microscope. Also on duty is "NanoSIMS", short
for the nanometer scaled secondary-ion mass spectrometer. Its task is to
analyze the mineralogy, chemical and isotopic composition of the
extraterrestrial dust particles.
Bradley
called the Stardust mission "a stunning success", one that far exceeded the
scientific community's most optimistic expectations. The particles snared
by Stardust are expected to provide insight into the early formation of our
solar system.
"Now
we begin the arduous task of photo-documentation, followed by years of great
science," Bradley concluded.
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