Luther is a small lunar

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

on the northwest part of Mare Serenitatis, at the inlet to Lacus Somniorum. To the east-southeast is the large crater

Posidonius Posidonius (; , "of Poseidon") "of Apameia" (ὁ Ἀπαμεύς) or "of Rhodes" (ὁ Ῥόδιος) (), was a Greeks, Greek politician, astronomer, astrologer, geographer, historian, mathematician, and teacher native to Apamea (Syria), Apame ...

. Luther has a circular rim and is cup-shaped, with no appreciable wear from impact erosion. It lies across a

wrinkle ridge A wrinkle ridge is a type of feature commonly found on lunar maria, or basalt plains. These features are low, sinuous ridges formed on the mare surface that can extend for up to several hundred kilometers. Wrinkle ridges are tectonic features ...

on the

lunar mare The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to ...

. The crater is named after German astronomer Robert Luther.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Luther.

References

* * * * * * * * * * * {{refend Impact craters on the Moon Mare Serenitatis