Authors: Robin Canup, Harold F. Levison, & Glen R. Stewart

Status: To appear in Astronomical Journal.

Abstract: The currently favored theory of lunar origin is the giant-impact hypothesis. Recent work that has modeled accretional growth in impact-generated disks (Ida, Canup and Stewart 1997) has found that systems with one or two large moons and external debris are common outcomes. In this paper we investigate the evolution of terrestrial multiple moon systems as they evolve due to mutual interactions (including mean-motion resonances) and tidal interaction with the Earth, using both analytical techniques and numerical integrations. We find that multiple moon configurations which form from impact-generated disks are typically unstable: these systems will likely evolve into a single moon state as the moons mutually collide or as the inner moonlet crashes into the Earth.

Click here for an encapsulated postscript file of this paper. This paper contains color figures. Click here for an encapsulated postscript file containing only the color figures.

Click here for a pdf file of this paper.