Depth/diameter relations of fresh lunar craters: Revision from spacecraft data


  • Richard J. Pike


The first systematic data from Apollo photogrammetry provide a high standard of accuracy for the depth/diameter (Ri/Dr) relation of fresh lunar craters. Apollo Ri/Dr results resemble results obtained by measuring shadows on Lunar Orbiter imagery. The Ri/Dr distribution inflects at a crater diameter of 10 km - 15 km. Lunar craters less than 15 km across are at least 50% deeper than older, telescopic data indicated (now, Ri is ∼0.2 Dr), but larger craters are not much deeper. There is no marked Ri/Dr difference between fresh upland and postmare craters. The new Ri/Dr relation for small lunar craters resembles those of experimental and impact craters on Earth.