Geological Chronicle
Neumayer is a lunar impact crater spanning 84.38 kilometers across in the Helmholtz quadrangle near the Moon's southern limb. Viewed from Earth, the crater appears heavily foreshortened and can only be observed during favorable lunar librations. It adjoins the southeastern rim of the slightly larger crater Helmholtz, with Demonax situated to the south-southwest and Hale to the east-southeast.
The formation dates to the Nectarian period on the lunar geologic timescale. A history of minor impacts has softened and rounded its features, though the rim remains intact and has not been significantly reshaped or indented by notable craters.
Scattered smaller craters mark its nearly flat, level floor, which lacks significant ridges or a central peak. A small craterlet rests on the floor near the northern rim, and the feature commemorates German meteorologist and hydrographer Georg Balthasar von Neumayer.