Bio/Description Born in Durban, South Africa, Professor Robert B. Hargraves received his B.Sc. from the University of Natal in 1948. From 1954 to 1956 he served with the U.S. Army. In 1959 he received his Ph.D. from Princeton, and he returned in 1961 as an assistant professor. Professor Hargraves was promoted to full professor in 1971. With roots in South Africa and in mineral exploration, Professor Hargraves is a field-oriented geologist whose career has been characterized by the discovery of intellectual “prospects” and then “mining” them for their scientific content. He was one of the earliest geologists in North America to recognize the reality and the consequences of plate tectonics. His career began with the discovery of a huge meteorite impact site in South Africa, and recently he discovered the largest impact site yet found in the United States. He applied his understanding of the unusual terrestrial rock called anorthosite to the interpretation of the returned Moon rocks and used his expertise on the magnetism of rocks for study of Martian red soils, for which he received NASA’s Exceptional Scientific Achievement Medal. Professor Hargraves carried the excitement of true discovery into the classroom, where his impatience with the ready acceptance of conventional wisdom has left a lasting impression on his students.