[meteorite-list] Raw Ingredients for Life Detected in Planetary Construction Zones

[Ron Baalke]

Nancy Neal/Dwayne Brown
Headquarters, Washington                  May 27, 2004
(Phone: 202/358-1547/1726)

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

RELEASE: 04-167

RAW INGREDIENTS FOR LIFE DETECTED IN PLANETARY CONSTRUCTION 
ZONES

     NASA has announced new findings from the Spitzer Space 
Telescope, including the discovery of significant amounts of 
icy organic materials sprinkled throughout several "planetary 
construction zones," or dusty planet-forming discs, which 
circle infant stars.

These materials, icy dust particles coated with water, 
methanol and carbon dioxide, may help explain the origin of 
icy planetoids like comets. Scientists believe these comets 
may have endowed Earth with some of its water and many of its 
biogenic, life-enabling materials.
 
Drs. Dan Watson and William Forrest of the University of 
Rochester, N.Y, identified the ices. They surveyed five very 
young stars in the constellation Taurus, 420 light-years from 
Earth. Previous studies identified similar organic materials 
in space, but this is the first time they were seen 
unambiguously in the dust making up planet-forming discs.

In another finding, Spitzer surveyed a group of young stars 
and found intriguing evidence that one of them may have the 
youngest planet detected. The observatory found a clearing in 
the disc around the star CoKu Tau 4. This might indicate an 
orbiting planet swept away the disc material, like a vacuum 
leaving a cleared trail on a dirty carpet. The new findings 
reveal the structure of the gap more clearly than ever 
before. Because CoKu Tau 4 is only about one million years 
old, the possible planet would be even younger. As a 
comparison, Earth is approximately 4.5-billion years old.

"These early results show Spitzer will dramatically expand 
our understanding of how stars and planets form, which 
ultimately helps us understand our origins," said Dr. Michael 
Werner, Spitzer project scientist at NASA's Jet Propulsion 
Laboratory (JPL), Pasadena, Calif., which manages the 
mission.

Spitzer also discovered two of the farthest and faintest 
planet-forming discs ever observed. These discs surround two 
of more than 300 newborn stars uncovered for the first time 
in a stunning new image of the dusty stellar nursery called 
RCW 49. It is approximately 13,700 light-years from Earth in 
the constellation Centaurus.

 "Preliminary data suggest all 300 or more stars harbor 
discs, but so far we've only looked closely at two. Both were 
found to have discs," said Dr. Ed Churchwell of the 
University of Wisconsin, Madison, Wis., principal 
investigator of the RCW 49 research, with Dr. Barbara Whitney 
of Space Science Institute, Boulder, Colo.

Planet forming, "protoplanetary," discs are a natural phase 
in a star's life. A star is born inside a dense envelope of 
gas and dust. Within this envelope, and circling the star, is 
a flat, dusty disc, where planets are born.

"By seeing what's behind the dust, Spitzer has shown us star 
and planet formation is a very active process in our galaxy," 
Churchwell said.

Spitzer's exquisitely sensitive infrared eyes can see planet 
forming discs in great detail. "Previously, scientists could 
study only a small sample of discs, but Spitzer is already on 
its way toward analyzing thousands of discs," Werner said.
 
Spitzer's infrared spectrograph instrument, which breaks 
apart infrared light to see the signatures of various 
chemicals, was used to observe the organic ices and the 
clearing within CoKu Tau 4's disc. Spitzer's infrared array 
camera found the new stars in RCW 49. Papers on the research 
will appear in the September 1, 2004, issue of the journal 
Astrophysical Journal Supplements. For images and information 
about the research on the Internet, visit:

http://www.spitzer.caltech.edu


http://photojournal.jpl.nasa.gov

For information about NASA and agency programs on the 
Internet, visit:

http://www.nasa.gov


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