Le Monnier is the remnant of a lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 that has been partly inundated by lava

Lava

Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 flows. It is located on the eastern edge of Mare Serenitatis

Mare Serenitatis

Mare Serenitatis is a lunar mare that sits just to the east of Mare Imbrium on the Moon.It is located within the Serenitatis basin, which is of the Nectarian epoch. The material surrounding the mare is of the Lower Imbrian epoch, while the mare material is of the Upper Imbrian epoch...

, and the western part of the rim is missing so that it now forms a large bay. To the north is the crater Chacornac

Chacornac (crater)

Chacornac is an irregular lunar impact crater attached to the southeast rim of the crater Posidonius. It lies just to the east of the Mare Serenitatis, and north of the crater Le Monnier....

.

The interior of this formation is relatively flat and smooth, with no significant craterlets to mark the surface. The outer rim is battered, worn, and notched with past impacts. Only slight wrinkle ridges now mark where the western rim once lay.

The landing site of the Luna 21

Luna 21

-External links:*...

 space probe is located near the southern rim of Le Monnier. Lunokhod 2

Lunokhod 2

Lunokhod 2 was the second of two unmanned lunar rovers landed on the Moon by the Soviet Union as part of the Lunokhod program....

, a robotic roving vehicle deposited on the surface by Luna 21, covered a distance of 37 kilometers across the crater floor. It also surveyed the southern edge of the crater rim.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Le Monnier.

Le Monnier	Latitude	Longitude	Diameter
A	26.9° N	32.5° E	21 km
H	25.0° N	29.6° E	6 km
K	27.7° N	30.2° E	4 km
S	26.8° N	33.9° E	40 km
T	25.1° N	31.4° E	18 km
U	26.1° N	33.5° E	25 km
V	26.0° N	34.3° E	23 km

The following craters have been renamed by the IAU

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

.

• Le Monnier B — See Very (lunar crater)
  Very (lunar crater)
  Very is a tiny lunar crater located in the eastern part of Mare Serenitatis, to the west-southwest of Le Monnier. It lies upon a wrinkle ridge that runs to the north and south named Dorsa Smirnov. The crater was previously known as Le Monnier B, a satellite crater of Le Monnier, before being...
  
  .
• Le Monnier C — See Borel (crater)
  Borel (crater)
  Borel is a tiny lunar impact crater located in the southeast part of Mare Serenitatis. To the northeast is the crater Le Monnier. Borel was previously identified as Le Monnier C before being named by the IAU....
  
  .

External links

• LTO-43A4 Le Monnier — L&PI topographic map
  Topographic map
  A topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, usually using contour lines in modern mapping, but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and man-made features...
  
  .