[meteorite-list] Stardust to Land at Carnegie

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Feb 3 12:51:52 2006
Message-ID: <200602031750.k13HoDa04648_at_zagami.jpl.nasa.gov>


Stardust to land at Carnegie
Carnegie Institution
February 1, 2006

Carnegie scientists breathed a sigh of relief on Sunday, January 15 when
NASA's Stardust mission landed safely with the first solid comet samples
ever brought back to Earth. As members of the mission's Preliminary
Examination Team, Larry Nittler and Conel Alexander (both Department of
Terrestrial Magnetism) with Marc Fries and George Cody (both Geophysical
Laboratory) will be among the first to get their hands on these precious
samples, captured from the coma of comet Wild-2. These tiny bits hold
clues to the formation of the solar system, and might even reveal how
organic molecules - the ingredients of life - first arrived on Earth.

"It has been an exciting week," Nittler said. "No one quite knew what to
expect when the team at Johnson Space Center opened the capsule, so when
we heard the collection grid was filled with particles, we could hardly
contain ourselves."

Scientists believe comets like Wild-2 are the oldest solid bodies in the
solar system. Yet until now, no one has seen a piece of a comet up
close. Researchers expect to retrieve less than one thousandth of an
ounce of material from Stardust's collection grid. By comparing the
structure and chemistry of Stardust grains to interstellar dust and rare
meteorites rich in organic material, researchers may be able to fill in
some significant holes concerning the evolution and history of our solar

"It is likely that some of the carbon in our bodies was originally bound
up in comets and delivered to the early Earth through impacts," Fries
explained. "So when we say that 'we are stardust' we are literally
talking about the type of material that Stardust has returned to our
laboratories for analysis."

Carnegie's share of the bounty is due to arrive in early February, and
the researchers are ready with a brand new, $2.8 million NanoSIMS ion
probe. Ion probes can reveal the chemical makeup of a sample by
vaporizing tiny target areas with a stream of ions, allowing an accurate
count of the elements emitted as a result; with much greater sensitivity
than previous ion probes, the NanoSIMS is an ideal tool for analyzing
minuscule Stardust grains.

Nittler, Alexander, Fries, and Cody also plan to study the physical and
chemical details of Stardust grains using two different spectroscopic
techniques. First, by analyzing laser light reflected from a sample,
Raman spectroscopy can reveal both the structure of minerals and the
forms of carbon present.

Second, a unique soft X-ray microscope at Lawrence Berkeley National
Laboratory's Advanced Light Source facility in California enables a
technique called XANES spectroscopy, which can help characterize the
carbon, nitrogen, and oxygen species in organic matter. Since the
carbon-containing materials from Wild-2 are likely to be unchanged since
the birth of the solar system, these analyses are especially important.

"We can't wait to get going on these experiments," Cody said. "Stardust
is really just the beginning; Carnegie now has the tools to take a
leading role in sample-return analysis for decades to come."

NASA provided funds in support of this work through the Stardust
Participating Scientist Program. NASA's Sample Return Laboratory
Instrument and Data Analysis (SRLIDA) program funded both the Raman
instrument and a portion of the cost of the NanoSIMS ion probe. NASA
also provided partial support for work at the Advanced Light Source, a
facility funded by the U.S. Department of Energy.

More information about the Stardust mission may be found at the
following two sites:


Received on Fri 03 Feb 2006 12:50:12 PM PST

Help support this free mailing list:

Yahoo MyWeb