The gravity field of a cube

Abstract

We calculate the Newtonian gravitational potential and field of a cubic, homogeneous asteroid and we apply it to the orbit of possible satellites. Large astronomical objects such as stars or planets, naturally tend to form spherical shapes due to the dominance of the gravitational forces, but as a thought experiment, we consider the properties of a planet in the form of a perfect cube. We investigate the formation of stable orbits around such cubic objects, for the case of a static as well as a rotating cube employing the method of Poincare sections. The calculation of the gravitational field around non-spherical objects has a significant role in space missions to investigate asteroid belt objects that require calculating orbits around a large non-spherical mass. The calculation of such non-spherical fields also has relevance in identifying deposits or beds of ores inside the Earth, by measuring gravitational anomalies.