Named in honor of Mark Robinson, a planetary geologist who has worked on M-type bodies (Mercury, Moon, Mars, and Minor Planets). He began his career in Alaska, where he prospected for mineral ores and earned his B.S. in geology at the University of Alaska. In Hawaii, he completed his doctorate in 1993 on lunar and martian volcanism and then began his outstanding work on the Clementine mission to the Moon as a member of the U.S. Geological Survey Astrogeology Branch. His efforts, which he continues from his new base at Northwestern University, are now directed to the NEAR spacecraft mission and to future exploration of Mercury. Citation prepared with the assistance of A. McEwen.