Non-Gravitational Forces in Planetary Systems

TL;DR

This paper reviews the significant roles of non-gravitational forces in planetary systems, affecting small bodies' behaviors and properties, with a focus on their physical characteristics and implications in the solar system and beyond.

Contribution

It provides order-of-magnitude descriptions and examples of non-gravitational forces, highlighting their importance and the challenges in measuring their physical properties.

Findings

Non-gravitational forces influence comet morphology and asteroid dynamics.

They affect meteorite delivery and debris disk evolution.

Physical properties governing these forces are often poorly known.

Abstract

Non-gravitational forces play surprising and, sometimes, centrally important roles in shaping the motions and properties of small planetary bodies. In the solar system, the morphologies of comets, the delivery of meteorites and the shapes and dynamics of asteroids are all affected by non-gravitational forces. In exoplanetary systems and debris disks, non-gravitational forces affect the lifetimes of circumstellar particles and feed refractory debris to the photospheres of the central stars. Unlike the gravitational force, which is a simple function of the well known separations and masses of bodies, the non-gravitational forces are frequently functions of poorly known or even unmeasurable physical properties. Here, we present order-of-magnitude descriptions of non-gravitational forces, with examples of their application.