[meteorite-list] UA Astronomer Is Scientist For Proposed 'Dawn' Discovery Mission

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:42:02 2004
Message-ID: <200101212134.NAA10224_at_zagami.jpl.nasa.gov>

News Services
University of Arizona
Tucson, Arizona

Contact Information:
Mark V. Sykes, 520-621-5381, msykes_at_as.arizona.edu

Jan 19, 2001

UA Astronomer is Scientist For Proposed 'Dawn' Discovery Mission
By Lori Stiles

A University of Arizona astronomer is one big step closer to two asteroids
that have recorded what the early solar system was like when the terrestrial
planets formed.

NASA's Office of Space Science has selected three proposals for detailed
study as candidates for the next Discovery mission to be launched in 2005-
2006. UA astronomer Mark V. Sykes is a scientist on the proposed "Dawn"
mission. The mission is led by Christopher T. Russell of the University of
California-Los Angeles.

"Dawn will study the conditions and processes of planet formation during
the earliest epoch of our solar system by orbiting and studying two of the
largest asteroids which have survived from this time, Ceres and Vesta,"
Sykes said. Dawn builds on decades of asteroid and meteorite studies, he
added.

"Ceres is more than a quarter the diameter of the moon, is water-rich, and
has retained its primitive composition and condition. Vesta, on the other
hand, was dry, heated to the point of melting, and preserves a record of
its subsequent differentiation.

"Almost all asteroids that we observe today are the fragments of larger
asteroids like Vesta and Ceres that were destroyed by ancient catastrophic
collisions. By studying Vesta and Ceres, we gain a much greater
understanding of how these modern fragments were once put together," Sykes
said.

Actually, scientists already have pieces of one of the asteroids within
reach -- as meteorites that landed on Earth.

"Cratering collisions have knocked off pieces of Vesta, which have been
recovered as meteorites. They provide us with detailed information on
geochemical processes that have occurred within specific sites on Vesta
from the time of its formation at the beginning of the solar system,"
Sykes said.

"Going to Vesta will give us the big picture within which these hand-sized
pieces fit. It will be like going from studying bits of hair, nail, and
bone to seeing and studying the entire animal up close for the first
time," he added.

Sykes, an associate astronomer at Steward Observatory, specializes in the
study of asteroids, comets and interplanetary dust. He is the Chair of
the Division for Planetary Sciences of the American Astronomical Society.

NASA selected Dawn and two other proposed missions, called Kepler and
INSIDE Jupiter, for further study from 26 proposals submitted last
August. Each selected team will receive $450,000 to conduct a 4-month
implementation -- feasibility study. One of the proposals will be
selected for full development late this year.

According to a UCLA news release, the Dawn mission is proposed to carry a
framing camera and mapping spectrometer provided by the German Aerospace
Center, DLR, Institute of Sensor Technology and Planetary Exploration in
Berlin; a laser altimeter experiment provided by the NASA Goddard Space
Flight Center in conjunction with the Massachusetts Institute of
Technology; a gamma ray/neutron spectrometer from the Department of
Energy's Los Alamos National Laboratory; and a magnetometer provided by
UCLA.

Ion engines would power the spacecraft to the asteroid belt, where it
first orbits Vesta in an ever-tightening circle and then spirals outward
and heads to its rendezvous with Ceres. Flybys of more than a dozen other
asteroids along the way are planned.

[NOTE: Images supporting this release are available at
http://uanews.opi.arizona.edu/cgi-bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=2937]
Received on Sun 21 Jan 2001 04:34:51 PM PST