Dix Planetary Science Seminar

Abstract: Earth-based and satellite observations reveal a distinct pattern of frequently active volcanic hotspots on the surface of Io. This pattern is associated with the heat flow originating from Io's non-uniformly tidally heated interior. The spatial pattern of dissipated heat depends on the rheological properties of Io's interior. The dissipated heat, however, simultaneously influences the rheology, due to the temperature-dependence of the mantle viscosity and melt fraction. To investigate the strength and characteristics of this feedback for Io, we developed a numerical model to calculate steady-state temperature profiles for a heterogeneously heated body.  Our results show that the resulting long-wavelength thermal heterogeneities cause only small viscosity contrasts for the deep mantle but significant lateral differences in the asthenosphere thickness and melt volume.

Abstract: Telescopic observations of water vapor around Ceres suggest the dwarf planet can generate an exosphere, but the possible source of this water vapor was not well characterized before the arrival of the Dawn spacecraft. In this talk, I discuss the possibility and likelihood that sublimating water ice could explain this exosphere, integrating what we know about the location and quantity of water ice on Ceres from Dawn data.