Main is a
lunar
Lunar most commonly means "of or relating to the Moon".
Lunar may also refer to:
Arts and entertainment
* ''Lunar'' (series), a series of video games
* "Lunar" (song), by David Guetta
* "Lunar", a song by Priestess from the 2009 album ''Prior t ...
impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
that is located near the north pole of the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
. 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
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ...
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 midpoint that is closest to Main.
References
*
*
*
*
*
*
*
*
*
*
*
*
{{refend
External links
LAC-1 area- Map of northern lunar pole
Impact craters on the Moon