Using Satellites to Probe Extrasolar Planet Formation

TL;DR

This paper predicts that primordial satellites form only around giant planets and that all satellites of terrestrial planets form via impacts, providing new insights into planetary system formation and history.

Contribution

It introduces two novel predictions about satellite formation mechanisms and their implications for understanding planetary system evolution.

Findings

Primordial satellites are exclusive to giant planets.

Terrestrial planet satellites form exclusively through impacts.

Satellite characteristics can constrain planetary system history.

Abstract

Planetary satellites are an integral part of the heirarchy of planetary systems. Here we make two predictions concerning their formation. First, primordial satellites, which have an array of distinguishing characteristics, form only around giant planets. If true, the size and duration of a planetary system's protostellar nebula, as well as the location of its snow line, can be constrained by knowing which of its planets possess primordial satellites and which do not. Second, all satellites around terrestrial planets form by impacts. If true, this greatly enhances the constraints that can be placed on the history of terrestrial planets by their satellites' compositions, sizes, and dynamics.