UC Santa Cruz

This thesis consists of three loosely related projects exploring the physics of planetary bodies. The throughline in this research is that I explore how a planetary body's interior influences its exterior -- in particular how heat migrating outward drives evolution and leaves detectable traces of that evolution. Chapter One describes a novel form of volcanism -- volcanism on iron bodies, which we call ferrovolcanism. We predict that metallic bodies were able to host volcanism, making metal the third major type of crustal material capable of being volcanic, in addition to ice and silicate planets. We discuss the potential for its observation by the Psyche mission, its role in the evolution of metallic bodies, and its potential influence on the metallic meteorite record. Chapter Two lays out a way to significantly improve Europa Clipper's ability to measure Europa's global shape, without requiring any extra measurements. By using stellar occultations, measurements that Europa Clipper was already planning to collect, we can supplement radar altimetry to obtain more complete global coverage of Europa. We demonstrated the potential for this combined dataset to significantly improve global fits, which would allow Europa Clipper to better constrain the thickness, rheology, and history of Europa's ice shell. Chapter Three explores the relationship between rotation rate and tidal dissipation in the interior of Jupiter's moon Io. This is motivated by two separate lines of thinking: 1) Io's volcanoes appear to be offset in longitude from where tidal dissipation models predict they should form, and 2) if a satellite is sufficiently fluid - plausible for Io because it is so strongly heated - it is expected to rotate slightly faster than the synchronous rotation rate we see across solar system satellites. We find that because of the rigidity of its lithosphere, we do not expect Io to rotate nonsynchronously on geophysically relevant timescales.