Named in honor of Bruce W. Hapke, planetary scientist at the University of Pittsburgh. A pioneer investigator of the physical and chemical nature of the surfaces of minor planets, he was one of the first to recognize the division of minor planets into two principal color classes (later known as C and S types) on the basis of UBV photometry. More recently, he has developed a comprehensive theoretical treatment of the scattering of sunlight in planetary regoliths. (M 12806) _ _.