Research Interests

My chief research effort has been the petrological study of chondritic meteorites as a source of information about the origin of the solar system. I have worked more consciously than most of my meteoriticist colleagues to relate meteorite properties to astrophysical models of solar system formation. I have also worked extensively in lunar sample studies (during the Apollo program), and I constructed global models of lunar formation and internal evolution. I was a member of the RADIG team the interpreted the radar data collected by the Magellan mission to Venus. In that connection I used thermodynamic methods to understand the mineral assemblages produced by weathering of primary surface rock in contract with the Venusian atmosphere. I have served on NASA advisory committees concerned with allocation of lunar samples to laboratory investigators, mission planning, and peer review of grant proposals. Currently I chair the Committee on Planetary and Lunar Exploration (COMPLEX), under the Space Studies Board of the NRC.

Membership Type


Election Year


Primary Section

Section 16: Geophysics

Secondary Section

Section 12: Astronomy