40 years of research experience with lunar petrology, geochemistry, and geochronology including Apollo samples and lunar meteorites. Broad knowledge of lunar geology, impact and volcanic history, physical and chemical characteristics of the Moon. Expertise in isotope geochemistry, mass spectrometry, and laser ablation analysis of geological materials. Research interests include the origin, evolution and impact history of the terrestrial planets, basaltic volcanism, ore deposit geochronology, and the geochemistry of dust and water in the environment. 140 peer-reviewed articles on various aspects of geochemistry and cosmochemistry. Executive Editor of Geochimica et Cosmochimica Acta, the premier intenational journal in geochemistry.