Gravity - Mare Humorum.

Abstract

Global tracking coverage of the Apollo 15 subsatellite has provided gravity measurements from 50 km altitudes over the entire Humorum basin. An estimate of surface mass points at 2 degree intervals, which best fit the data reveals a mass distribution having a lesser mass excess for the very central area. When two different profiles were fit using a two disk model it was again found for each profile that the smaller central disk decreased the central mass by approximately 30%. The mass distribution per unit area however for the major portion of the mascon is still consistent with the other mascons (Crisium, Nectaris and Serenitatis) of approximately 800-900 kg/sq cm. The surface mass point solution seems to correlate somewhat with the dark areas on Whitaker's IR-UV map.