Impact melting and vaporization of the Earth-Moon system.

The goal the project is to determine the thermodynamic properties of silicate liquids that control the response of rocky plants to large impacts using first principles molecular dynamics simulations. Such simulations have already had an important impact on our views of magma ocean evolution, for example, leading to the idea of the basal magma ocean. A coordinated suite of new simulations are needed to make progress. In particular the pressure-temperature regime relevant to large impacts remains unexplored: a symmetric impact at Keplerian velocity generates a peak pressure of 1000 GPa (1 TPa), 7 times the pressure at the base of Earth's mantle. Yet learning about material behavior at these conditions is essential for understanding the consequences if large impacts, including the depth of melting, and the amount and composition of vapor produced on release. The results will provide a rich source of information on the physical properties of silicate liquids, and will constrain the fundamental thermodynamic relation of silicate liquids over the entire pressure-temperature regime relevant to large impacts and the magma ocean.