TY - JOUR
T1 - Carbonaceous chondrites as analogs for the composition and alteration of Ceres
AU - McSween, Harry Y.
AU - Emery, Joshua P.
AU - Rivkin, Andrew S.
AU - Toplis, Michael J.
AU - C. Castillo-Rogez, Julie
AU - Prettyman, Thomas H.
AU - De Sanctis, M. Cristina
AU - Pieters, Carle M.
AU - Raymond, Carol A.
AU - Russell, Christopher T.
N1 - Funding Information:
Acknowledgments—We thank E. Bullock and T. McCord for reviews. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA, and at the Institute for Space Astrophysics and Planetology, Italian National Institute for Astrophysics. GRaND is operated by the Planetary Science Institute under contract with JPL.
Publisher Copyright:
© The Meteoritical Society, 2017.
PY - 2018/9
Y1 - 2018/9
N2 - The mineralogy and geochemistry of Ceres, as constrained by Dawn's instruments, are broadly consistent with a carbonaceous chondrite (CM/CI) bulk composition. Differences explainable by Ceres’s more advanced alteration include the formation of Mg-rich serpentine and ammoniated clay; a greater proportion of carbonate and lesser organic matter; amounts of magnetite, sulfide, and carbon that could act as spectral darkening agents; and partial fractionation of water ice and silicates in the interior and regolith. Ceres is not spectrally unique, but is similar to a few other C-class asteroids, which may also have suffered extensive alteration. All these bodies are among the largest carbonaceous chondrite asteroids, and they orbit in the same part of the Main Belt. Thus, the degree of alteration is apparently related to the size of the body. Although the ammonia now incorporated into clay likely condensed in the outer nebula, we cannot presently determine whether Ceres itself formed in the outer solar system and migrated inward or was assembled within the Main Belt, along with other carbonaceous chondrite bodies.
AB - The mineralogy and geochemistry of Ceres, as constrained by Dawn's instruments, are broadly consistent with a carbonaceous chondrite (CM/CI) bulk composition. Differences explainable by Ceres’s more advanced alteration include the formation of Mg-rich serpentine and ammoniated clay; a greater proportion of carbonate and lesser organic matter; amounts of magnetite, sulfide, and carbon that could act as spectral darkening agents; and partial fractionation of water ice and silicates in the interior and regolith. Ceres is not spectrally unique, but is similar to a few other C-class asteroids, which may also have suffered extensive alteration. All these bodies are among the largest carbonaceous chondrite asteroids, and they orbit in the same part of the Main Belt. Thus, the degree of alteration is apparently related to the size of the body. Although the ammonia now incorporated into clay likely condensed in the outer nebula, we cannot presently determine whether Ceres itself formed in the outer solar system and migrated inward or was assembled within the Main Belt, along with other carbonaceous chondrite bodies.
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U2 - 10.1111/maps.12947
DO - 10.1111/maps.12947
M3 - Article
AN - SCOPUS:85052614476
SN - 1086-9379
VL - 53
SP - 1793
EP - 1804
JO - Meteoritics and Planetary Science
JF - Meteoritics and Planetary Science
IS - 9
ER -