[meteorite-list] Student Research Cracks Origin Story of Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 4 Mar 2016 12:48:49 -0800 (PST)
Message-ID: <201603042048.u24Kmnx2009936_at_zagami.jpl.nasa.gov>


FSU Student Research Cracks Origin Story of Meteorite
Kathleen Haughney
February 25, 2016

A Florida State University student has cracked the code to reveal the
deep and interesting history of an ancient meteorite that likely formed
at the time our planets were just developing.

Jonathan Oulton, a 2015 FSU graduate, working with Earth, Ocean & Atmospheric
Science Professor Munir Humayun, studied the pieces of a meteorite called
Gujba. Using sophisticated lasers and mass spectrometers at the FSU-headquartered
National High Magnetic Field Laboratory, Humayun and Oulton conducted
in-depth chemical analysis of the meteorite samples that shattered previous
theories about when and how this meteorite had formed.

"We tried to elucidate a story about its origins through this science,"
said Oulton, who is now pursuing a doctoral degree at University of Colorado.

Previously, scientists believed that Gujba was formed more or less from
the dust of the solar system.

But, as Humayun and Oulton analyzed it, they discovered it had a far more
complex geological history than previously thought. They inferred that
Gujba formed from the debris of a collision between a parent planet that
had both a crust and mantle, something that would only be found on a fairly
large planet of the kind that is not seen today in the asteroid belt.

A piece of the meteorite Gujba.

To get that type of formation, Gujba would have been involved in more
than the equivalent of a solar system fender bender.

Oulton, Humayun and their collaborators argue that Gujba formed from the
molten debris produced when a large metallic body smashed into another
planet and both bodies were destroyed in the process. Based on chemical
traces preserved in Gujba, the target planet might have been even larger
than the asteroid 4 Vesta, one of the largest bodies in the asteroid belt
with a diameter of about 326 miles or 525 kilometers.

"People used to say that meteorites like Gujba were the building blocks
of the solar system," Humayun said. "Now, we know it's the construction
debris of the planets, to borrow a phrase from Ed Scott of the University
of Hawaii."

The research will be published in an upcoming issue of Geochimica et Cosmochimica
Acta, but is currently available online.

Oulton presented the preliminary results of the paper at the 2015 Lunar
& Planetary Science Conference and received the Dwornik Award of the Geological
Society of America for the best undergraduate presentation.

"In a broad sense, people have been trying forever to understand how we
got here," Oulton said. "Although this doesn't get to that directly, this
research gives us a greater understanding of the physical chemistry of
everything that occurred at the time the Earth formed."

Oulton served as the lead author on the article. Other researchers on
the paper are Lawrence Grossman and Alexei Fedkin of The University of
Received on Fri 04 Mar 2016 03:48:49 PM PST

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