Alfred Wegener and the Origin of Lunar Craters

Alfred Wegener is universally known for his work on continental drift, but Wegener also made an interesting contribution, just after the First World War, to the study of lunar craters. Wegener reviewed the various hypotheses for lunar cratering, evaluated them from the standpoint of physics, and then performed a series of simple but ingenious experiments from which he concluded that the craters were impact phenomena, occasionally accompanied by secondary melting. This work was probably more important for the theory of scale models in geophysical experiments than it was to the history of selenology, but Wegener's view that lunar craters were impact phenomena and (perhaps more significantly) the reasoning on which he based this conclusion are now generally accepted, along with his once-scorned ideas on continental mobility.