 LRO WAC image | |
| Coordinates | 45°18′N151°24′E / 45.3°N 151.4°E Coordinates: 45°18′N151°24′E / 45.3°N 151.4°E |
|---|---|
| Diameter | 219 km |
| Depth | Unknown |
| Colongitude | 212° at sunrise |
| Eponym | Leon Campbell William W. Campbell |
Campbell is a large lunar impact crater that is located in the northern hemisphere on the far side of the Moon. It lies to the southwest of the walled plain D'Alembert, an even larger formation. If Campbell were located on the near side of the Moon as seen from the Earth, it would form one of the largest visible craters, being slightly larger than Schickard. It is bordered by several craters of note, with Wiener to the southwest, Von Neumann just to the south, Ley overlying the southeast rim, and Pawsey to the west.
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, almost all of which were formed by impacts.
An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters range from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.
Earth's Moon is an astronomical body that orbits the planet and acts as its only permanent natural satellite. It is the fifth-largest satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits. The Moon is, after Jupiter's satellite Io, the second-densest satellite in the Solar System among those whose densities are known.
This formation has been heavily worn and eroded by a history of impacts, leaving a circular rim that is an irregular ring of ridges and peaks. Multiple small craters lie along the rim and the inner wall, as well as across the interior floor. The most notable of these are Campbell X along the northeast inner rim and Campbell N near the southern inner wall.
Much of the inner floor is covered by a multitude of lesser impacts; the exception being a wide patch of the floor that has been resurfaced by basaltic lava. This area has a lower albedo than its surroundings, thus appearing dark. It stretches from the center of Campbell towards the western rim, and has an irregular perimeter.
Basalt is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. Basalt lava has a low viscosity, due to its low silica content, resulting in rapid lava flows that can spread over great areas before cooling and solidification. Flood basalt describes the formation in a series of lava basalt flows.
Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption, usually at temperatures from 700 to 1,200 °C. The structures resulting from subsequent solidification and cooling are also sometimes described as lava. The molten rock is formed in the interior of some planets, including Earth, and some of their satellites, though such material located below the crust is referred to by other terms.
Albedo is the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body. It is dimensionless and measured on a scale from 0 to 1.
There is an unusual crater lying to the south of Campbell and to the west of Von Neumann. This is formed by two or more overlapping craters, the most recent being Wiener F, a nearly hexagonal formation with a rugged interior.
