Geological Chronicle
Positioned in a lava-flooded region west of Mare Tranquillitatis, Cayley spans 14.2 kilometers across its circular rim. The impact crater sits north-northwest of De Morgan and D'Arrest, while Whewell lies to the west with about the same dimensions. To the north, the linear rille Rima Ariadaeus follows a course to the east-southeast.
Dating to the Eratosthenian age on the lunar geologic timescale, Cayley is a bowl-shaped crater with a small interior floor occupying about one-fourth of its total cross-section. Its sloping interior walls have a higher albedo than the surrounding terrain, though it lacks a ray system. Spectral and chemical data from the Clementine mission indicate this impact did not excavate any cryptomare material.
The smooth, rolling plains to the east are known as the Cayley Formation, which lunar scientists suspect formed from deposits of ejecta from large impact basins such as Mare Imbrium. William R. Birt and John Lee introduced the crater's name in the 19th century in honor of English mathematician Arthur Cayley, and the International Astronomical Union officially adopted the designation in 1935.