Lunar global figure from mare surface elevations

Laser altimetry data from the Apollo 15, 16, and 17 missions show that the ringed maria surfaces lie on one particular reference surface and that the center of gravity is definitely displaced from the optical center. If these extensive surfaces are assumed to be near hydrostratic surfaces, then there must have existed a time in lunar history when lunar tides and/or internal processes were much different than they are today.This paper presents one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract NAS 7-100, sponsored by the National Aeronautics and Space Administration.