Mach is a large 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 ...

of the class known as a walled plain. It is located on the far side of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

and cannot be viewed directly from the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. Nearby craters of note include

Joule The joule ( , or ; symbol: J) is the unit of energy in the International System of Units (SI). In terms of SI base units, one joule corresponds to one kilogram- metre squared per second squared One joule is equal to the amount of work d ...

to the northeast,

Mitra ''Mitra'' (Proto-Indo-Iranian language, Proto-Indo-Iranian: wikt:Reconstruction:Proto-Indo-Iranian/mitrás, ''*mitrás'') is the name of an Indo-Iranians#Religion, Indo-Iranian divinity that predates the Rigveda, Rigvedic Mitra (Hindu god), Mitrá ...

attached to the western outer rim, and Henyey to the southwest. This is a prominent but eroded formation with multiple craters along the rim and interior. The crater Harvey breaks across the eastern rim, and its outer

rampart Rampart may refer to: * Rampart (fortification), a defensive wall or bank around a castle, fort or settlement Rampart may also refer to: * LAPD Rampart Division, a division of the Los Angeles Police Department ** Rampart scandal, a blanket ter ...

spills across the interior floor of Mach. The overall shape of Mach resembles a

pear Pears are fruits produced and consumed around the world, growing on a tree and harvested in late summer into mid-autumn. The pear tree and shrub are a species of genus ''Pyrus'' , in the Family (biology), family Rosaceae, bearing the Pome, po ...

, with a prominent outward bulge to the northeast. Such a bulge can be caused by a second, merged crater. The northern edge is also the most worn and overlain by impacts. The interior of Mach is marked by several small craters, particularly in the northeastern bulge. Several craters also lie along the edges to the west and northwest. The remainder of the interior floor is relatively level, when compared to the

terrain Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...

that surrounds Mach. There is a formation of central ridges near the midpoint of the crater. Mach lies to the northeast of the Dirichlet–Jackson Basin.

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 Mach.

References

* * * * * * * * * * * * {{refend Impact craters on the Moon Ernst Mach