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

[Ron Baalke]

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 
	
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