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Abundance of presolar grains in comet Wild 2 and
implications for transport and mixing in the solar
nebula.
Stadermann F. J. and Floss C. (2008)
Lunar & Planet. Sci. 39, Abstract #1889.
ABSTRACT
In early 2006 NASA's Stardust mission successfully
returned samples from comet Wild 2 for laboratory analysis.
Among the surprise discoveries during the preliminary
examination (PE) of the cometary matter was the observation
that these samples are not just mixtures of ice and
interstellar grains as previously speculated, but contain
significant fractions of high-temperature minerals from the
inner solar system. Only a single presolar grain with
extremely anomalous O isotopic composition was found during
the PE, indicating a relatively low presolar grain
abundance. We have continued our search for presolar
material in samples from Wild 2 by performing isotope
imaging searches in C, N, O, and S at high spatial
resolution and located two more presolar grains in the
cometary material. With this additional data we can
determine the presolar grain abundance in the Wild 2 samples
with better statistical significance, compare the abundance
to those in other types of solar system materials, and draw
conclusions about basic solar nebula properties.
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