Dwarf planet Ceres as an icy and accessible frozen ocean world

Ceres, the largest object in the asteroid belt, is the only dwarf planet to have been orbited by spacecraft.  If Ceres is icy, it is an especially useful cornerstone to learn about the more distant moons and ocean worlds of the outer solar system.  However, most current literature concludes that Ceres has fairly low ice content, in large part because it is argued that Cerean topography requires minimal ice to be maintained over time.  Here, I will instead argue that the most compelling interpretation of NASA’s Dawn data is that Ceres has a very icy interior structure: nearly pure ice at the surface that gradually becomes more impure with depth.  In particular, recent rheological experiments combined with our geophysical simulations of deforming topography show that an ice shell can be far stronger than previously thought, removing the primary objection to an icy interpretation of Ceres’ interior structure.  Our preferred interior structure is consistent with a progressively freezing ocean that became more impurity-rich as it solidified.  I will discuss how a future NASA mission at the New Frontiers level can test these and other ideas on the evolution of Ceres and its water.

Speaker: Michael Sori, Purdue University

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Room 350/372