Density-depth model for the lunar outermost layer

Abstract

It is increasingly evident that the density of the lunar outermost layer varies with depth, but models for the density-depth profile are scarce. Other models are vaguely stated without use of explicit mathematical expressions. A mathematical model for density as a function of depth is proposed which satisfies the known evidence and for which a plausible physical argument can be given. Comparison with other models is made, and the proposed model is found to compare favorably with the Matveev model. It is also consistent with recent estimates of density obtained from the Surveyor spacecraft, microwave thermal emission, and radar reflection.