The evolution of the moon - A finite element approach

The present lunar evolution model analyzes the thermal history of a self-gravitating spherical planetary body, including the effects of viscous dissipation, internal melting, adiabatic gradient, core formation, variable viscosity, radioactive nucleide decay, and a depth-dependent initial temperature profile, together with physical parameters corresponding to the moon. Although no initial basalt ocean is assumed, partial melting is observed early in the model moon's history. This is suggested to be related to the formation of the basalt maria. The model's present lithospheric thickness is 600 km, with core-mantle temperatures close to 1600 K and surface heat flux of 25.3 mW/sq m. The finite element method is judged to be applicable to the problem of planetary evolution, although faster solution algorithms will be required for the examination of a sufficient number of models.