[meteorite-list] NASA's Spitzer and Deep Impact Build Recipe for Comet Soup

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Sep 7 17:14:18 2005
Message-ID: <200509072113.j87LDD023046_at_zagami.jpl.nasa.gov>

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Whitney Clavin (818) 354-4673
Jet Propulsion Laboratory, Pasadena, Calif.

News Release 2005-144 Sept. 7, 2005

NASA's Spitzer and Deep Impact Build Recipe for Comet Soup

When Deep Impact smashed into comet Tempel 1 on July 4,
2005, it released the ingredients of our solar system's
primordial "soup." Now, astronomers using data from
NASA's Spitzer Space Telescope and Deep Impact have
analyzed that soup and begun to come up with a recipe
for what makes planets, comets and other bodies in our
solar system.

"The Deep Impact experiment worked," said Dr. Carey
Lisse of Johns Hopkins University's Applied Physics
Laboratory, Laurel, Md. "We are assembling a list of
comet ingredients that will be used by other scientists
for years to come." Lisse is the team leader for Spitzer's
observations of Tempel 1. He presented his findings this
week at the 37th annual meeting of the Division of
Planetary Sciences in Cambridge, England.

Spitzer watched the Deep Impact encounter from its lofty
perch in space. It trained its infrared spectrograph on
comet Tempel 1, observing closely the cloud of material
that was ejected when Deep Impact's probe plunged below
the comet's surface. Astronomers are still studying the
Spitzer data, but so far they have spotted the signatures
of a handful of ingredients, essentially the meat of comet
soup.

These solid ingredients include many standard comet
components, such as silicates, or sand. And like any good
recipe, there are also surprise ingredients, such as clay
and chemicals in seashells called carbonates. These
compounds were unexpected because they are thought to
require liquid water to form.

"How did clay and carbonates form in frozen comets?" asked
Lisse. "We don't know, but their presence may imply that
the primordial solar system was thoroughly mixed together,
allowing material formed near the Sun where water is
liquid, and frozen material from out by Uranus and Neptune,
to be included in the same body."
 
Also found were chemicals never seen before in comets, such
as iron-bearing compounds and aromatic hydrocarbons, found
in barbecue pits and automobile exhaust on Earth.

The silicates spotted by Spitzer are crystallized grains
even smaller than sand, like crushed gems. One of these
silicates is a mineral called olivine, found on the
glimmering shores of Hawaii's Green Sands Beach.

Planets, comets and asteroids were all born out of a thick
soup of chemicals that surrounded our young Sun about 4.5
billion years ago. Because comets formed in the outer,
chilly regions of our solar system, some of this early
planetary material is still frozen inside them.

Having this new grocery list of comet ingredients means
theoreticians can begin testing their models of planet
formation. By plugging the chemicals into their formulas,
they can assess what kinds of planets come out the other
end.

"Now, we can stop guessing at what's inside comets," said
Dr. Mike A'Hearn, principal investigator for the Deep
Impact mission, University of Maryland, College Park.
"This information is invaluable for piecing together how
our own planets as well as other distant worlds may have
formed."

NASA's Jet Propulsion Laboratory, Pasadena, Calif.,
manages the Spitzer Space Telescope mission for NASA's
Science Mission Directorate, Washington. Science
operations are conducted at the Spitzer Science Center
at Caltech. The University of Maryland, College Park,
conducted the overall mission management for Deep Impact,
and JPL handled project management for the mission for
NASA's Science Mission Directorate.

For more graphics and more information about Spitzer,
visit

http://www.spitzer.caltech.edu/Media/index.shtml .

For more information about Deep Impact, visit

http://deepimpact.jpl.nasa.gov or

http://www.nasa.gov/deepimpact .

For more information about NASA, visit

http://www.nasa.gov/home/ .

      -end-
Received on Wed 07 Sep 2005 05:13:12 PM PDT