Dix Planetary Science Seminar

Abstract: The giant impact that formed the Moon left Earth rotating rapidly and substantially melted and vaporized. After the impact, radiative cooling and the tidal recession of the Moon transformed the Earth into the solid, slowly rotating planet we know today. Recovery is a key stage in Earth's evolution, but many facets of this period have not been studied. I will demonstrate that the internal pressures in the post-impact Earth could have been much lower than the present day. For example, the core-mantle boundary (CMB) pressure could have been as low as 60 GPa, compared to ~136 GPa in the present-day Earth. As Earth cooled and the Moon receded, the pressures in Earth increased over tens of millions of years.I will examine the consequences of Earth's evolving pressure, and discuss how variations in post-impact evolution could be used to differentiate between Moon-formation scenarios.