Ralph Belknap Baldwin

Ralph Belknap Baldwin (June 6, 1912 – October 23, 2010) was an American planetary scientist known for his work on lunar craters, beginning in the late 1940s. His book, The Face of the Moon made the case for the impact nature of lunar craters. He published The Measure of the Moon in 1963.

Prior to his lunar work he was Senior Physicist at Johns Hopkins University's Applied Physics Laboratory during World War II working on the proximity fuze. He died on October 23, 2010. After graduation, he taught astronomy at the University of Michigan, University of Pennsylvania, and Northwestern University from 1935 through 1942. During World War II Baldwin helped to develop the radar proximity fuze. He published a history of proximity fuze development in 1980 entitled The Deadly Fuze.

Awards and honors Baldwin has been honored for each of his three careers. During his work on the radio proximity fuze he was awarded the Army Chief of Ordnance Award and the U.S. Naval Bureau Ordnance Award (1945).

In planetary science he has been awarded the Barringer Medal (2000), Leonard Medal (1986), G.K. Gilbert Award (1986) and the J. Lawrence Smith Medal (1979).