LPL Colloquium: Dr. Alyssa Rhoden

Mimas, that’s no (ocean) moon! Or is it?

Dr. Alyssa Rhoden
Principal Scientist
Southwest Research Institute, Boulder

Mimas is the innermost “regular” moon of Saturn. It’s small and heavily cratered, suggesting that Mimas lacked sufficient internal heating to drive geologic activity. However, Cassini measurements of its libration require that Mimas either has a non-hydrostatic core or a subsurface ocean, and the phase of the libration is more consistent with an ocean. Either interpretation implies that Mimas is differentiated, challenging traditional models of its formation, evolution, and age. Determining whether Mimas has an ocean today will help constrain the possible histories of Mimas and its neighboring moons. Also, if Mimas were shown to have an ocean, it would represent a new class of small, “stealth” ocean worlds, whose surfaces do not betray the ocean’s existence. I will describe the current state of knowledge about this curious moon, whether estimates of tidal heating support the presence of an ocean despite Mimas’ high eccentricity, and how we might be able to use spacecraft measurements to determine whether Mimas is, indeed, an ocean moon today. 

More information about Dr. Alyssa Rhoden's research

Host: Dr. Erik Asphaug


Tuesday, January 25, 2022 - 3:45pm