[meteorite-list] Sutter's Mill Meteorite Preserved For Present and Future Scientists

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 21 Aug 2013 09:59:37 -0700 (PDT)
Message-ID: <201308211659.r7LGxbqT014548_at_zagami.jpl.nasa.gov>

http://carsonnow.org/story/08/21/2013/rare-meteorite-preserved-present-and-future-scientists
 
Rare meteorite preserved for present and future scientists
by Jeff Munson
Carson Now
August 21, 2013

The main mass of a rare meteorite observed in the skies over Carson City,
Carson Valley and Lake Tahoe that exploded over California's Sierra foothills
in April 2012 will be preserved for current and future scientific discoveries,
thanks to the collaborative efforts of five U.S. academic institutions.

It has found a permanent home divided among the University of California,
Davis; the Smithsonian Institution's National Museum of Natural History
in Washington, D.C.; American Museum of Natural History in New York City;
The Field Museum of Natural History in Chicago; and Arizona State University
in Tempe. Together, the institutions have successfully acquired the biggest
known portion of the Sutter's Mill meteorite.

The meteorite is considered to be one of the rarest types to hit the Earth
-- a carbonaceous chondrite containing cosmic dust and presolar materials
that helped form the planets of the solar system.

Its acquisition signifies enhanced research opportunities for each institution
and ensures that future scientists can study the meteorite for years to
come.

"With these museums and institutions storing the meteorite's main mass,
it leaves it in a pristine condition to preserve for future generations
to study," said UC Davis geology professor Qing-zhu Yin. "Fifty or 100
years from now, we may have new technology that will enable later generations
to revisit the meteorite and do research we haven't thought of. This gives
us a better chance to realize the full scientific value of the meteorite,
rather than have it be just a collector's item."

The meteorite formed about 4.5 billion years ago. While it fell to Earth
roughly the size of a minivan before exploding as a fireball, less than
950 grams have been found. Its main mass weighs just 205 grams (less than
half a pound) and is about the size of a human palm.

The main mass was X-rayed by CT scan at the UC Davis Center for Molecular
and Genomic Imaging. This was the first time a meteorite acquisition was
CT scanned before its division among a consortium of institutes, allowing
prior knowledge of each piece's contents. Then it was cut into five portions,
reflective of each institution's investment, before being delivered to
the institutions.

The portion of the main mass acquired by each institution includes:

* American Museum of Natural History: 34 percent
* Smithsonian Institution's National Museum of Natural History: 32 percent
* The Field Museum of Natural History: 16 percent
* Arizona State University: 13 percent
* UC Davis: 5 percent

When the meteorite landed near Sutter's Mill, the gold discovery site
that sparked the California Gold Rush, it spurred a scientific gold rush
of sorts, with researchers, collectors and interested citizens scouring
the landscape for fragments of meteorite. The institutions that have acquired
the main mass were among those that acted on this rare scientific opportunity
to gain insights about the origins of life and the formation of the planets.

At UC Davis, for instance, the meteorite fell just 60 miles east of the
main campus. Yin immediately traveled to the site with students and colleagues,
looking for specimens and reaching out to the public to provide meteorite
donations for science. He confirmed for the original discoverer of the
main mass that it was carbonaceous chondrite. Yin and his UC Davis colleagues
have also X-rayed the meteorite and determined its age and chemical composition.

"It just happened in our backyard,' said Yin. "I felt obligated to do
something, and I still do."

Involvement from the other institutions included:

* The American Museum of Natural History worked closely with Yin to secure
specimens of the Sutter's Mill meteorite right after its fall, and performed
nondestructive computed tomography (CT) scans of several specimens kindly
loaned by their finders. These scans were used to determine the density
of several samples to very high accuracy, confirming the type of meteorite
represented by Sutter's Mill.

* The Field Museum of Natural History found several presolar stardust
grains in two smaller pieces of the meteorite donated by private collector
Terry Boudreaux. Presolar stardust grains are the oldest solid samples
available to any lab and are essentially time capsules from before the
solar system formed 4.6 billion years ago.

* Arizona State University's Meenakshi Wadhwa, director of the Center
for Meteorite Studies, was contacted by Robert Haag, the private collector
who owned the main mass. She then contacted the other institutions to
initiate its joint acquisition.

* The Smithsonian Institution cut the mass into five portions.

Last spring, UC Davis alumnus Gregory Jorgensen and donor Sandy VanderPol
provided nearly 3 grams of the Sutter's Mill meteorite to Yin's lab at
UC Davis. Those 3 grams allowed UC Davis to learn the meteorite's age
and chemical composition. The university's recent acquisition of another
10 grams of the main mass will allow for even further research, including
searching for presolar grains and performing isotopic analysis.

UC Davis' section of the meteorite was funded by a portion of Yin's Chancellor's
Fellowship.
Received on Wed 21 Aug 2013 12:59:37 PM PDT