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| Titel |
Imaging spectroscopy of HED meteorites |
| VerfasserIn |
M. C. De Sanctis, E. Ammannito, A. Coradini |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250028967
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| Zusammenfassung |
| Imaging spectroscopy is an important and efficient tool to measures spectral characteristics of
meteorites and terrestrial rocks. We have applied this technique to a suite of HEDs (
Howardite, Eucrite and Diogenite) meteorites of the Antarctic Meteorites Collection
managed by the US Antarctic Meteorite Program. This activity was done to support the
scientific interpretation of the hyper-spectral data produced by VIR-MS, the imaging
spectrometer aboard the Dawn mission to small bodies 1 Ceres and 4 Vesta. The
majority of meteorites are believed to be derived from parent bodies in the asteroid
belt, even though there are few specific asteroids identified as sources. One of the
exceptions is the association of Vesta with the Howardite, Eucrite, Diogenite class of
achondrites (HEDs). HEDs are a clan of achondritic meteorites that have continuous
variations in mineralogy and chemistry. Pyroxenes are the dominant mafic mineral
present in HED meteorites and provide multiple clues about how the parent body
evolved.
VIS reflectance spectroscopy techniques has been applied to slices extracted
from the Eucrite meteorite LEW88005 and we are measuring the diogenite EET
A79002.
We acquired a hyperspectral image in the visual spectral range (0.25–0.95 μm) of both
side of the sample. In the data cube are clearly recognizable clasts and regions with different
reflectance value. In many of the spectra can be recognized the 1 μm band, typical of
pyroxenes. Some others, especially the dark regions, are spectra typical of glasses even if a
little percentage of pyroxenes is still present. In a first analysis we can say that pyroxenes
seem to be present everywhere in the sample, at the resolution of 0.25 mm (spatial resolution
of the images). The distribution and the percentage of pyroxenes changes along the sample:
we have measured different band strengths in different regions of the sample. The larger
amount of pyroxenes is found in the center of the bright clasts and we have recognize a
gradual increasing of the impurities going toward the dark matrix. This work is still
going on, in particular we are analyzing the spectra in order to extract quantitative
information that can help understanding of the thermal history of the sample and thus
the one of Vesta, the possible parent body of the Eucrites. Furthermore, we are
now measuring the other HED slabs, in order to found differences and analogies. |
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