Constraints on the origin of viscoelastic bodies

While the oceans undoubtly contribute to energy dissipation, it seems implausible that such a small amount (0.02%) of the Earth's mass could play such a dominant role in lunar orbital evolution. An alternate hypothesis assumes that most of the dissipation is associated with solid-body tides. This mechanism is also capable of varying significantly over time for viscoelastic bodies. In such an analysis of orbital evolution, the bodies are modeled as incompressible, Kelvin-Voight solids. While this material is simplistic, it does provide an analytical characterization of solid-body dissipation and the resulting tidal moment. The orbital history of a two body system is traced back in time to develop constraints on the satellite's origin. These constraints suggest the Moon appeared in a significantly inclined orbit at a distance greater than ten Earth radii. This distance is outside of the Roche limit and would appear to alleviate some difficulties associated with capture hypotheses. Small eccentricity at close approach suggests an origin by accretion.