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Arnold (crater)
Encyclopedia
Arnold is a lunar
crater
that is located in the north-northeastern part of the visible Moon
, near the lunar limb. This location gives the crater a notably oval appearance due to foreshortening, although the formation is actually relatively round. It lies to the northeast of the Mare Frigoris
, to the north of the crater Democritus
. West of Arnold is the smaller crater Moigno
.
The ancient rim of Arnold has been worn and rounded by ages of subsequent bombardment. There is a gap in the wall to the southwest, marked by the tiny crater Arnold J, and the wall is relatively low along the eastern edge. The northern half of the rim is the most intact, particularly to the northeast where is joins the satellite crater Arnold A.
The inner floor of Arnold crater has been resurfaced by lava
, and is relatively flat except for a number of tiny craterlets. The most notable crater in the interior is Arnold F, in the northwest section. If the crater once possessed a central peak, no sign of this feature now remains.
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 is located in the north-northeastern part of the visible 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...
, near the lunar limb. This location gives the crater a notably oval appearance due to foreshortening, although the formation is actually relatively round. It lies to the northeast of the Mare Frigoris
Mare Frigoris
Mare Frigoris is a lunar mare located just north of Mare Imbrium, and stretches east to north of Mare Serenitatis. The mare is in the outer rings of the Procellarum basin...
, to the north of the crater Democritus
Democritus (crater)
Democritus is a lunar impact crater that is located on the northern part of the Moon, just to the north of the Mare Frigoris. Just to the south of Democritus is the lava-flooded crater Gärtner, which forms a bay on the mare. Directly to the north is Arnold, another flooded formation.The rim of...
. West of Arnold is the smaller crater Moigno
Moigno (crater)
Moigno is a lunar crater that is located in the northern part of the Moon's near side. It lies just to the west of the crater Arnold, and southeast of Neison. The low rim of this crater is worn and eroded, until it is nearly level with the surrounding terrain. The perimeter is only roughly...
.
The ancient rim of Arnold has been worn and rounded by ages of subsequent bombardment. There is a gap in the wall to the southwest, marked by the tiny crater Arnold J, and the wall is relatively low along the eastern edge. The northern half of the rim is the most intact, particularly to the northeast where is joins the satellite crater Arnold A.
The inner floor of Arnold crater has been resurfaced 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...
, and is relatively flat except for a number of tiny craterlets. The most notable crater in the interior is Arnold F, in the northwest section. If the crater once possessed a central peak, no sign of this feature now remains.
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 Arnold.| Arnold | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 68.8° N | 39.8° E | 57 km |
| E | 71.6° N | 38.3° E | 32 km |
| F | 67.5° N | 35.2° E | 10 km |
| G | 67.3° N | 31.4° E | 11 km |
| H | 72.6° N | 45.3° E | 13 km |
| J | 65.9° N | 33.7° E | 6 km |
| K | 70.8° N | 42.8° E | 29 km |
| L | 70.2° N | 36.1° E | 33 km |
| M | 68.3° N | 43.6° E | 7 km |
| N | 70.2° N | 41.9° E | 18 km |