Planetary Science

I study planetary bodies in our solar system as an opportunity to test our understanding of important geophysical processes that are either difficult to isolate or occur within very limited conditions on Earth. One such process is tidal interaction between moons & their host planet (or the planet and the star). My research assesses the role of tidal processes in the evolution of planetary bodies in our solar system and for exoplanets. One of my key areas of interest is the interior structure and potential habitability of icy ocean worlds (e.g., Enceladus, Europa, Titan, Pluto, and Ceres) where tidal deformation is the dominant geophysical forcing.

My work demonstrates that tidal processes significantly influence planetary system architecture. For instance, my analysis of the orbital evolution of Phobos, a moon of Mars, showed that Phobos will likely break-up to form a Martian ring system in about 20-40 Myr [Black & Mittal 2015]. My work on icy ocean worlds has been primarily focused on Enceladus, a small moon of Saturn with vigorous polar jets and high astrobiological potential. With Doug Hemingway, I used global gravity-topography-interior structure modeling to provide robust estimates of Enceladus’s interior structure and showed that most tidal dissipation in Enceladus occurs in the ice shell [Hemingway & Mittal, 2019]. I also used my results for Enceladus’s ice shell structure in global ocean circulation models (with oceanographers Wanying Kang & John Marshall) to demonstrate the dominant role of seawater salinity for ocean dynamics on icy moons and the strong coupling of ocean dynamics and ice shell thickness variations [Kang, Mittal et al. 2020].