Morphological indicators of a mascon beneath Ceres' largest crater, Kerwan

Geophysical Research Letters
By: , and 

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Abstract

Gravity data of Ceres returned by the National Aeronautics and Space Administration's Dawn spacecraft is consistent with a lower density crust of variable thickness overlying a higher density mantle. Crustal thickness variations can affect the long‐term, postimpact modification of impact craters on Ceres. Here we show that the unusual morphology of the 280 km diameter crater Kerwan may result from viscous relaxation in an outer layer that thins substantially beneath the crater floor. We propose that such a structure is consistent with either impact‐induced uplift of the high‐density mantle beneath the crater or from volatile loss during the impact event. In either case, the subsurface structure inferred from the crater morphology is superisostatic, and the mass excess would result in a positive Bouguer anomaly beneath the crater, consistent with the highest‐degree gravity data from Dawn. Ceres joins the Moon, Mars, and Mercury in having basin‐associated gravity anomalies, although their origin may differ substantially.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Morphological indicators of a mascon beneath Ceres' largest crater, Kerwan
Series title Geophysical Research Letters
DOI 10.1002/2017GL075526
Volume 45
Issue 3
Year Published 2018
Language English
Publisher American Geophysical Union
Contributing office(s) Astrogeology Science Center
Description 8 p.
First page 1297
Last page 1304