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LPSC abstracts on solar system isotopes
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- Subject: LPSC abstracts on solar system isotopes
- From: Peter Abrahams <telscope@europa.com>
- Date: Wed, 04 Mar 1998 09:15:27 -0800
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Abstracts for the 29th Lunar & Planetary Science Conference, March 1998,
are at
http://cass.jsc.nasa.gov/meetings/LPSC98/pdf/sess42.pdf
The session on ‘Solar System Isotopes and Solar Nebula Processes’ includes
these papers:
Condensation of the solar nebula began with high temperature mineral
corundum and proceeded through the condensation of lower temperature
minerals. A database of 18 elements and 665 species of gas and condensate
was assembled, with a code for equilibrium calculations at various phases
in the cooling of the nebula. More reduced or oxidized systems can also be
modeled. (Petaev)
The chemistry of the early solar nebula is based on calculations that often
do not include the time it takes for a chemical reaction to occur.
Although these intervals are a very brief time on these scales, the
efficiency of the reaction can sometimes be determined by the rate of the
reaction. Evaporation of enstatite was a key reaction in forming the
constituents of the solar system. A laboratory experiment involving single
crystals of orthoenstatite in a vacuum at 1500 degrees C, produced
forsterite crystals. Further work using hydrogen is needed. (Tachibana)
The Indarch EH4 chondrite was used in a study of manganese / chromium
ratios. Evidence was found implying that the E chondrites formed near 1.5
earth orbits from the sun. This would require their parent bodies to be
transported to the asteroid belt. The chromium isotopes in Indarch show
similarities to Martian minerals, possibly indicating that Mars formed
partly from similar material. A tentative age for the Indarch parent body
is approximately 4,564 million years (with the solar system being about
4,571 million years old). The Indarch parent body is therefore a very
early planetesimal, which was not significantly metamorphized. (Shukolyukov)
_______________________________________
Peter Abrahams telscope@europa.com
the history of the telescope, the microscope,
and the prism binocular