Main (lunar crater)
Encyclopedia
Main is a lunar
crater
that is located near the north pole of the Moon
. The southern rim of this formation has merged with the larger crater Challis
to the south, and the level interior floor connects the two craters through a narrower gap. To the north-northwest of Main is Gioja
.
This formation consists of three overlapping craters that were joined together when the interior floor was resurfaced by lava
flows, leaving a generally circular formation with outward bulges to the west and northeast. The same lava has joined the floor of Main with Challis to the south.
The surviving rim of Main is a low slope that is nearly level with the surrounding terrain at its top. There is a small crater lying across the eastern rim that is roughly bowl-shaped and missing its western rim. The floor of Main is nearly level, and marked by a number of tiny craterlets that lie nearly in a band across the floor from the southwest towards the northeast. There is no central peak within the crater, and no other hills of note.
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 near the north pole 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...
. The southern rim of this formation has merged with the larger crater Challis
Challis (crater)
Challis is a lunar crater that is located in the northern regions of the Moon's near side, close enough to the limb to appear significantly foreshortened when viewed from the Earth...
to the south, and the level interior floor connects the two craters through a narrower gap. To the north-northwest of Main is Gioja
Gioja (crater)
Gioia is a lunar crater that is located in the vicinity of the north pole of the Moon. It is named after the Italian inventor Flavio Gioia. As it lies so close to the northern limb, it is view nearly from the edge making difficult to observe from the Earth. The crater is attached to the southern...
.
This formation consists of three overlapping craters that were joined together when the interior floor was 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...
flows, leaving a generally circular formation with outward bulges to the west and northeast. The same lava has joined the floor of Main with Challis to the south.
The surviving rim of Main is a low slope that is nearly level with the surrounding terrain at its top. There is a small crater lying across the eastern rim that is roughly bowl-shaped and missing its western rim. The floor of Main is nearly level, and marked by a number of tiny craterlets that lie nearly in a band across the floor from the southwest towards the northeast. There is no central peak within the crater, and no other hills of note.
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 Main.| Main | Latitude | Longitude | Diameter |
|---|---|---|---|
| L | 81.7° N | 23.2° E | 14 km |
| N | 82.3° N | 22.0° E | 11 km |