COMPOSITIONAL HOMOGENEITY OF CM PARENT BODIES
Name
Vernazza_2016_AJ_152_54.pdf
Description
Published version
Size
1.13 MB
Format
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Checksum (MD5)
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Author(s)
Vernazza, P.
Marsset, M.
Beck, P.
Binzel, R. P.
Birlan, M.
Cloutis, E. A.
DeMeo, F. E.
Dumas, C.
Hiroi, T.
Date Issued
August 2016
Journal
Astronomical Journal
Publisher
American Astronomical Society
Citation
Vernazza, P., Marsset, M., Beck, P., Binzel, R. P., Birlan, M. et al. 2016. "COMPOSITIONAL HOMOGENEITY OF CM PARENT BODIES." Astronomical Journal, 152 (3).
Version
Final published version
Abstract
© 2016. The American Astronomical Society. All rights reserved. CM chondrites are the most common type of hydrated meteorites, making up ∼1.5% of all falls. Whereas most CM chondrites experienced only low-temperature (∼0°C-120°C) aqueous alteration, the existence of a small fraction of CM chondrites that suffered both hydration and heating complicates our understanding of the early thermal evolution of the CM parent body(ies). Here, we provide new constraints on the collisional and thermal history of CM-like bodies from a comparison between newly acquired spectral measurements of main-belt Ch/Cgh-type asteroids (70 objects) and existing laboratory spectral measurements of CM chondrites. It first appears that the spectral variation observed among CM-like bodies is essentially due to variations in the average regolith grain size. Second, the spectral properties of the vast majority (unheated) of CM chondrites resemble both the surfaces and the interiors of CM-like bodies, implying a "low" temperature (<300°C) thermal evolution of the CM parent body(ies). It follows that an impact origin is the likely explanation for the existence of heated CM chondrites. Finally, similarly to S-type asteroids and (2) Pallas, the surfaces of large (D > 100 km) - supposedly primordial - Ch/Cgh-type main-belt asteroids likely expose the interiors of the primordial CM parent bodies, a possible consequence of impacts by small asteroids (D < 10 km) in the early solar system.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
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DOI of Published Version
https://doi.org/10.3847/0004-6256/152/3/54
