[meteorite-list] Genesis Mission Suggests Sun And Planets Constructed Differently

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 23 Jun 2011 12:11:52 -0700 (PDT)
Message-ID: <201106231911.p5NJBqEh004394_at_zagami.jpl.nasa.gov>

June 23, 2011

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle at jpl.nasa.gov
RELEASE: 11-199

NASA MISSION SUGGESTS SUN AND PLANETS CONSTRUCTED DIFFERENTLY

WASHINGTON -- Analysis of samples returned by NASA's Genesis mission
indicates our sun and its inner planets may have formed differently
than scientists previously thought.

The data revealed slight differences in the types of oxygen and
nitrogen present on the sun and planets. The elements are among the
most abundant in our solar system. Although the differences are
slight, the implications could help determine how our solar system
evolved.

The air on Earth contains three different kinds of oxygen atoms, which
are differentiated by the number of neutrons they contain. Nearly 100
percent of oxygen atoms in the solar system are composed of O-16, but
there also are tiny amounts of more exotic oxygen isotopes called
O-17 and O-18. Researchers studying the oxygen of Genesis samples
found that the percentage of O-16 in the sun is slightly higher than
on Earth, the moon, and meteorites. The other isotopes' percentages
were slightly lower.

"The implication is that we did not form out of the same solar nebula
materials that created the sun -- just how and why remains to be
discovered," said Kevin McKeegan, a Genesis co-investigator from the
University of California, Los Angeles and the lead author of one of
two Science papers published this week.

The second paper detailed differences in the amount of nitrogen on the
sun and planets. Like oxygen, nitrogen has one isotope, N-14, that
makes up nearly 100 percent of the atoms in the solar system, but
there also is a tiny amount of N-15. Researchers studying the same
samples saw that when compared to Earth's atmosphere, nitrogen in the
sun and Jupiter has slightly more N-14, but 40 percent less N-15.
Both the sun and Jupiter appear to have the same nitrogen
composition.

"These findings show that all solar system objects, including the
terrestrial planets, meteorites and comets, are anomalous compared to
the initial composition of the nebula from which the solar system
formed," said Bernard Marty, a Genesis co-investigator from Centre de
Recherches Petrographiques et Geochimiques in Nancy, France and the
lead author of the second new Science paper. "Understanding the cause
of such a heterogeneity will impact our view on the formation of the
solar system."

Data were obtained from analysis of Genesis samples collected from the
solar wind -- the material ejected from the outer portion of the sun.
This material can be thought of as a fossil of our nebula because the
preponderance of scientific evidence suggests that the outer layer of
our sun has not changed measurably for billions of years.

"The sun houses more than 99 percent of the material currently in our
solar system so it's a good idea to get to know it better," said
Genesis principal investigator Don Burnett of the California
Institute of Technology in Pasadena, Calif. "While it was more
challenging than expected we have answered some important questions,
and like all successful missions, generated plenty more."

Genesis launched in August 2000. The spacecraft traveled to Earth's L1
Lagrange Point about 1 million miles from Earth, where it remained
for 886 days between 2001 and 2004, passively collecting solar-wind
samples.

On Sept. 8, 2004, the spacecraft released a sample return capsule,
which made a hard landing as a result of a failed parachute in the
Utah Test and Training Range in Dugway, Utah. This marked NASA's
first sample return since the final Apollo lunar mission in 1972, and
the first material collected beyond the moon. NASA's Johnson Space
Center in Houston curates the samples and supports analysis and
sample allocation.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the
Genesis mission for NASA's Science Mission Directorate in Washington.
The Genesis mission was part of the Discovery Program managed at
NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed
Martin Space Systems in Denver developed and operated the spacecraft.
Analysis at the Centre de Recherches Petrographiques et Geochimiques
was supported by the Centre National d'Etudes Spatiales and the
French National Center for Scientific Research in Paris.
For more information on the Genesis mission, visit:

http://genesismission.jpl.nasa.gov
        
-end-
Received on Thu 23 Jun 2011 03:11:52 PM PDT