Nearch (crater)
Encyclopedia
Nearch is a lunar
impact crater
that is located in the southeastern part of the Moon
, to the southeast of the crater Hommel
. North of Nearch is Vlacq
, and to the northeast lies Rosenberger
. The crater is 76 kilometers in diameter and 2.9 kilometers deep. It is from the Pre-Nectarian
period, 4.55 to 3.92 billion years ago.
The outer rim of Nearch has been worn by smaller impacts, and is overlain by a few more significant craters along the eastern rim. The most notable of these is Nearch A, a 43-kilometer-diameter crater that intrudes into the southeastern rim of Nearch. Small craters have also disrupted the rim to the north and west. The remainder of the rim is relatively intact, and retains its generally circular form.
The inner walls of the crater slope down to a relatively level interior floor. This bottom floor is nearly featureless except for a few tiny craterlets scattered across the surface. In the southeast, the ejecta from Nearch A has produced a slightly more irregular region.
Nearch is named after Nearchus
, a 4th-century BC Greek navigator.
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...
impact 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 is located in the southeastern part of the Moon
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...
, to the southeast of the crater Hommel
Hommel (crater)
Hommel is a lunar crater located in the southeast section of the Moon, in a region that is deeply impacted with a multitude of impact craters. The most notable craters nearby are Pitiscus to the north; Rosenberger due east; and Nearch to the southeast. The prominent crater Vlacq is nearly attached...
. North of Nearch is Vlacq
Vlacq (crater)
Vlacq is a prominent lunar impact crater that is located in the southeastern part of the Moon, and appears foreshortened when viewed from the Earth. This crater is adjacent to the northeastern rim of the larger Hommel, and to the northwest rim of Rosenberger....
, and to the northeast lies Rosenberger
Rosenberger (crater)
Rosenberger is an old lunar impact crater in the southeastern part of the Moon. Due to foreshortening, this crater appears oval when viewed from the Earth. From orbit, however, the crater rim is nearly circular....
. The crater is 76 kilometers in diameter and 2.9 kilometers deep. It is from the Pre-Nectarian
Nectarian
The Nectarian Period of the lunar geologic timescale runs from 3920 million years ago to 3850 million years ago. It is the period during which the Nectaris Basin and other major basins were formed by large impact events...
period, 4.55 to 3.92 billion years ago.
The outer rim of Nearch has been worn by smaller impacts, and is overlain by a few more significant craters along the eastern rim. The most notable of these is Nearch A, a 43-kilometer-diameter crater that intrudes into the southeastern rim of Nearch. Small craters have also disrupted the rim to the north and west. The remainder of the rim is relatively intact, and retains its generally circular form.
The inner walls of the crater slope down to a relatively level interior floor. This bottom floor is nearly featureless except for a few tiny craterlets scattered across the surface. In the southeast, the ejecta from Nearch A has produced a slightly more irregular region.
Nearch is named after Nearchus
Nearchus
Nearchus was one of the officers, a navarch, in the army of Alexander the Great. His celebrated voyage from India to Susa after Alexander's expedition in India is preserved in Arrian's account, the Indica....
, a 4th-century BC Greek navigator.
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 Nearch.| Nearch | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 60.1° S | 40.1° E | 43 km |
| B | 60.9° S | 35.8° E | 43 km |
| C | 62.2° S | 35.8° E | 41 km |
| D | 57.0° S | 38.0° E | 10 km |
| E | 61.4° S | 33.9° E | 11 km |
| F | 62.9° S | 37.9° E | 8 km |
| G | 63.3° S | 39.8° E | 5 km |
| H | 57.6° S | 40.6° E | 9 km |
| J | 57.6° S | 37.4° E | 7 km |
| K | 57.9° S | 35.3° E | 13 km |
| L | 58.4° S | 35.6° E | 18 km |
| M | 58.4° S | 35.0° E | 7 km |