Shaping Rocky Planets: Insights from Impact Dynamics in Planetary Formation

Also on Zoom here: https://u-paris.zoom.us/j/3129957938?pwd=S2lISUFkSzVXNk52UFNYS1pzRkN2dz09 The last 200 million years of planetary formation have been marked by energetic collisions, potentially capable of resetting the thermochemical state of growing proto-planets and shaping their evolution. These impact events play a crucial role in determining the distinct characteristics of rocky/terrestrial planets within the solar system and are key to understanding phenomena such as the onset of plate tectonics on Earth and the presence of liquid water on its surface. In this seminar, we delve into various effects triggered by these collisions, including (1) collisional erosion, (2) melting leading to magma ocean formation, and (3) metal-silicate mixing within such magma oceans. We demonstrate the significance of impact parameters in determining collision outcomes. Because the impact parameters and impact frequency depend on the dynamics within the proto-planetary disk, we explore various accretion scenarios, although these have primarily been tested in the context of collisional erosion.