Cayley (crater)
Encyclopedia
Cayley is a small lunar
impact crater
that is located in a lava
-flooded region to the west of Mare Tranquillitatis
. It lies to the northwest of the smaller crater De Morgan
and the larger D'Arrest
. West and slightly north of Cayley is Whewell
, a crater of about the same dimensions. To the north is a linear rille
designated Rima Ariadaeus, which follows a course to the east-southeast.
This is a circular, bowl-shaped formation with a small interior floor at the mid-point. (Small being relative to the overall diameter, as it occupies about one-fourth the total cross-section.) The sloping interior walls are relatively light in hue, having a higher albedo
as the surrounding terrain. However it is not nearly as bright as the slightly larger crater Dionysius
to the east-southeast, and lacks a ray system
.
The smooth, rolling plains to the east of this crater are called the Cayley Formation. It is somewhat similar to the lunar maria, but has a slightly higher albedo
and is overlapped at the eastern edge by the Mare Tranquillitatis
. Lunar scientists suspect that this plain may have resulted from deposits of ejecta from the formation of large impact basins such as Mare Imbrium
or Mare Orientale
. (The most likely source is the Mare Imbrium
impact basin to the northwest.)
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 a 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...
-flooded region to the west of Mare Tranquillitatis
Mare Tranquillitatis
Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch. The surrounding mountains are thought to be of the Lower Imbrian epoch, but...
. It lies to the northwest of the smaller crater De Morgan
De Morgan (crater)
De Morgan is a small lunar impact crater that is located in the central region of the Moon, mid-way between the crater D'Arrest two crater diameters to the south, and Cayley to the north. It is named after British logician Augustus De Morgan....
and the larger D'Arrest
D'Arrest (crater)
D'Arrest is a lunar crater that is located in the lava-flooded region to the west of the Mare Tranquillitatis. It lies to the southeast of the crater Agrippa and northwest of Delambre...
. West and slightly north of Cayley is Whewell
Whewell (crater)
Whewell is a lunar impact crater that lies on a stretch of lava-resurfaced terrain to the west of Mare Tranquillitatis. It is located to the east of the disintegrated crater Tempel and north-northwest of D'Arrest...
, a crater of about the same dimensions. To the north is a linear rille
Rille
Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...
designated Rima Ariadaeus, which follows a course to the east-southeast.
This is a circular, bowl-shaped formation with a small interior floor at the mid-point. (Small being relative to the overall diameter, as it occupies about one-fourth the total cross-section.) The sloping interior walls are relatively light in hue, having a higher albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
as the surrounding terrain. However it is not nearly as bright as the slightly larger crater Dionysius
Dionysius (crater)
Dionysius is a lunar impact crater that lies on the western edge of the Mare Tranquillitatis. To the southeast is the crater pair of Ritter and Sabine. Just to the northwest is the system of rilles designated Rimae Ritter. These clefts follow a generally northwest direction.The rim of Dionysius is...
to the east-southeast, and lacks a ray system
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
.
The smooth, rolling plains to the east of this crater are called the Cayley Formation. It is somewhat similar to the lunar maria, but has a slightly higher albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
and is overlapped at the eastern edge by the Mare Tranquillitatis
Mare Tranquillitatis
Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch. The surrounding mountains are thought to be of the Lower Imbrian epoch, but...
. Lunar scientists suspect that this plain may have resulted from deposits of ejecta from the formation of large impact basins such as Mare Imbrium
Mare Imbrium
Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...
or Mare Orientale
Mare Orientale
Mare Orientale is one of the most striking large scale lunar features, resembling a target ring bull's-eye. Located on the extreme western edge of the lunar nearside, this impact basin is difficult to see from an Earthbound perspective.Material from this basin was not sampled by the Apollo program...
. (The most likely source is the Mare Imbrium
Mare Imbrium
Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...
impact basin to the northwest.)