Giant impacts stochastically change the internal pressures of terrestrial planets.

ABSTRACT: Pressure is a key parameter in the physics and chemistry of planet formation and evolution. Previous studies have erroneously assumed that internal pressures monotonically increase with the mass of a body. Using smoothed particle hydrodynamics and potential field method calculations, we demonstrate that the hot, rapidly rotating bodies produced by giant impacts can have much lower internal pressures than cool, slowly rotating planets of the same mass. Pressures subsequently increase because of thermal and rotational evolution of the body. Using the Moon-forming impact as an example, we show that the internal pressures after the collision could have been less than half that in present-day Earth. The current pressure profile was not established until Earth cooled and the Moon receded, a proc

SUBMITTER: Lock SJ 

PROVIDER: S-EPMC6726449 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature