[meteorite-list] All in the Family: Scientists Find Mother and Daughter Asteroids

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:47:09 2004
Message-ID: <200111081656.IAA12206_at_zagami.jpl.nasa.gov>

Geological Society of America
Boulder, Colorado

Contact:
Ann Cairns, Director of Communications and Marketing
acairns_at_geosociety.org, 303-357-1056

Written by Kara LeBeau, GSA Staff Writer

FOR IMMEDIATE RELEASE: November 8, 2001

GSA Release No. 01-59

All in the Family: Scientists Find Mother and Daughter Asteroids

There are asteroids and there are asteroids. Most were once part of
larger "parent bodies" and some supply meteorites that plunge to Earth.

But how do you trace the family line of asteroids? Scientists compare
mineralogy of asteroids by analyzing their near-infrared spectra. They
also compare asteroids' orbits around the sun. And recently they found
a perfect match -- "uniting" in a scientific sense, mother and daughter
asteroids.

"We determined the mineralogy of asteroid 1929 Kollaa and found that
it was once part of a larger asteroid called 4 Vesta. I was inspired
to observe these objects because they belong to the rare V-class of
asteroids, and they have orbits about the Sun that are very similar,"
explained Michael Kelley from NASA's Johnson Space Center. "Vesta is
the asteroid for which the V-class was established. Until now, no
mineralogical analysis had ever been done on another V-type. In that
sense, Vesta was unique until our recent work was done. We found not
only that this second V-class asteroid, 1929 Kollaa, was once part
of Vesta, but that it is also related to a very specific group of
meteorites."

Kelley will present this new discovery on Thursday, November 8, at
the Geological Society of America's annual meeting in Boston.

Most planetary scientists believe that 4 Vesta is the source of
howardite, eucrite, and diogenite meteorites (HED) found on Earth, but
Kelley points out that it is not a direct process. "Vesta is located
in a part of the main asteroid belt that makes it almost impossible
for it to deliver meteorites directly to Earth. So there are probably
intermediate asteroids, which were once part of Vesta, located in more
favorable orbits that provide delivery."

One of the ramifications of this discovery is that it will help
scientists build a geologic map of the asteroid belt and understand
what forces have acted on asteroids in the past. This information,
along with asteroids' mineralogy, would be crucial if there was ever
a need to prevent an asteroid from striking the Earth and causing a
major disaster.

CONTACT INFORMATION

During the GSA Annual Meeting, November 4-8, contact Ann Cairns or
Christa Stratton at the GSA Newsroom in the Hynes Convention Center,
Boston, Massachusetts, for assistance and to arrange for interviews:
(617) 954-3214.

The abstract for this presentation is available at:
     http://gsa.confex.com/gsa/2001AM/finalprogram/abstract_20247.htm

Post-meeting contact information:

Michael S. Kelley
NASA Johnson Space Center
Code SR
2101 NASA Rd. 1
Houston, TX 77058
E-mail: michael.kelley1_at_jsc.nasa.gov
Phone: 281-244-5119
Fax: 281-483-1573

Ann Cairns
Director of Communications
Geological Society of America
Phone: 303-357-1056
Fax: 303-357-1074
E-mail: acairns_at_geosociety.org
Received on Thu 08 Nov 2001 11:56:11 AM PST