Ibn Yunus (crater)
Encyclopedia
Ibn Yunus is the remains of a flooded lunar
crater
. It lies on the far side of the Moon
, just past the eastern limb. It can only be viewed from Earth
under conditions of favorable libration
and lighting, and even then it is seen from the edge. This feature is attached to the east-southeastern outer rim of the flooded crater Goddard
. It lies within the Mare Marginis
, a lunar mare
along the eastern limb.
What survives of this crater is a low, roughly circular ridge projecting up through the mare. This ring is broken along the western and southern edges, and the interior floor is covered by a nearly level surface with a relatively low albedo
.
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...
. It lies on the far side 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...
, just past the eastern limb. It can only be viewed from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
under conditions of favorable libration
Libration
In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...
and lighting, and even then it is seen from the edge. This feature is attached to the east-southeastern outer rim of the flooded crater Goddard
Goddard (crater)
Goddard is a lunar crater that is located along the eastern limb of the Moon, and so is visible from the edge from Earth. It is best viewed during favorable librations when the orientation of the Moon brings it further into sight. The crater is located in the Mare Marginis, to the northeast of the...
. It lies within the Mare Marginis
Mare Marginis
Mare Marginis is a lunar mare that lies on the very edge of the lunar nearside. The selenographic coordinates of this feature are 13.3° N, 86.1° E, and the diameter is 420 km. The name is Latin for "Sea of the Edge"....
, a lunar mare
Lunar mare
The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich compositions, and...
along the eastern limb.
What survives of this crater is a low, roughly circular ridge projecting up through the mare. This ring is broken along the western and southern edges, and the interior floor is covered by a nearly level surface with a relatively low 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...
.