Planet Formation & Geodynamics
The initial composition and thermo-chemical state of a planet determine how its climate and geodynamics will evolve - for instance, whether the planet will have an internal magnetic field. These conditions are in turn a direct product of planet formation processes. My research focuses on two key areas: a) understanding primary planet formation processes, especially planetesimal formation and giant impacts, and how observations can help constrain theoretical models; b) exploring the sensitivity of key planetary properties (e.g., global magnetic field, style of mantle convection) to the initial state of the planet.
My work has focused on theoretical and observational analyses of protoplanetary disks: coupled gas-dust dynamics during planetesimal formation [Mittal & Chiang 2015] and constraints on structure and composition of dust using infrared spectroscopy (with Christine Chen, Casey Lisse, Space Telescope Science Institute/APL) [Chen, Mittal et al. 2014; Mittal et al. 2015]. Using dust radiative transfer modeling and novel data analysis methods, I showed that many planetary systems have both an asteroid and a Kuiper belt, analogous to our solar system. My results also provided key observational constraints for the role of impacts during accretion of rocky planets [Mittal et al. 2015].
In order to assess how a planet’s geodynamics are affected by its initial conditions, I developed a new thermo-chemical framework for the Earth’s thermal evolution, core-mantle chemical interaction, and geodynamo [Mittal et al. 2019]. Using this framework, I demonstrated for the first time that mantle dynamics and composition control the rate of light element (e.g., Mg, Si, O) precipitation from the core. My analysis showed that this precipitation process can continuously generate a global magnetic field throughout Earth’s history.