Immediate origin of the Moon as a post-impact satellite: partial disruption

A visualisation of a 3D SPH simulation of a giant impact onto the early Earth that could explain the origin of the Moon immediately after the collision, in contrast with the traditional later growth from a debris disk. This opens up new options for the early Moon's orbit, composition, and internal structure. (Kegerreis et al. 2022, ApJL 937:L40 ) Above a high resolution threshold for simulations, we find that even satellites that initially pass so close to Earth that they might be torn apart (within the “Roche limit“) can not only survive partial disruption but also be launched onto wider, stable orbits. Depending on the scenario, satellites can also be placed directly into wide and more circular orbits, far above the Roche limit: The simulation data are rendered using Houdini and Redshift, from simulations using our open-source code SWIFT (). The colour, opacity, and emiss