DIX Planetary Science Seminar

Rocky materials likely dominate the interiors of some massive planets, from Uranus and Neptune to the many super-Earths and sub-Neptunes beyond our solar system. The states and behavior of rocks at several thousand gigapascals and tens of thousands of kelvins, characteristic of these planets, remain poorly understood, as such conditions lie beyond routine experimental reach. With growing geophysical data from the outer planets and an exploding catalog of exoplanets, understanding rocky materials under these extreme conditions has become an imperative. In this talk, I will introduce our efforts to develop a comprehensive model of rocky materials for massive planets from first-principles quantum mechanical calculations and thermodynamic modeling. Using MgSiO3 as an example, I will present results on the thermodynamic properties (e.g., thermal expansivity, heat capacity, the Grüneisen parameter) and phase equilibria of its solids and fluids, and preliminary results on the transport properties (e.g., electrical conductivity) of its supercritical fluid. These material properties are foundational for modeling the structure, dynamics, and evolution of massive planets, and I will conclude by discussing one simple application of our results to lava worlds.