Ceres' evolution and present state constrained by shape data

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.008 Byline: Julie C. Castillo-Rogez (a), Thomas B. McCord (b) Keywords: Geophysics Abstract: We model Ceres' thermo-physical-chemical evolution by considering a large range of initial conditions as well as various evolutionary scenarios. Models are constrained by available shape measurements, which point to a differentiated interior for Ceres. We address the role played by hydrothermal activity in the long-term evolution of Ceres and especially the evolution of its hydrosphere. We suggest that models with times of formation shorter than about 5My after the production of calcium-aluminum inclusions are more likely to undergo hydrothermal activity in their early history, which affects Ceres' long-term thermal evolution. We evaluate the conditions for preserving liquid water inside Ceres, a possibility enhanced by its warm surface temperature and the enrichment of its hydrosphere in a variety of chemical species. However, thermal modeling of the hydrosphere needs to be further investigated. We show that shape data can help constrain the amount of hydrated silicate in the core, and thus the extent of hydrothermal activity in Ceres. We discuss the importance of these results for the Dawn mission's arrival at Ceres in 2015. Author Affiliation: (a) Jet Propulsion Laboratory, California Institute of Technology, M/S 79-24, 4800 Oak Grove Drive, Pasadena, CA 91109, USA (b) The Bear Fight Center, P.O. Box 667, 22 Fiddler's Road, Winthrop, WA 98862, USA Article History: Received 19 November 2008; Revised 10 April 2009; Accepted 17 April 2009