Hubble (crater)
Encyclopedia
Hubble is a lunar
crater
that lies very near the east-northeastern limb of the Moon
. At this location it is viewed almost from the side from Earth
, and the visibility of this feature is affected by libration
. It lies to the north of the Mare Marginis
and northeast of the crater Cannon
. About one crater diameter to the north-northeast is Lyapunov
.
The rim of this crater is worn and eroded, and it has a somewhat irregular edge in places. The inner wall is wider along the western side, where the rim has a slight outward bulge. The most intact portion of the rim lies along the eastern side, and the inner wall of this face is visible from the Earth.
The interior floor has been resurfaced by basalt
ic lava
, giving it a lower albedo
than the surrounding terrain. It is, however, not quite as dark as the lunar mare
to the south. This surface is relatively level and featureless, with only a few tiny craterlets. It lacks a central peak, but a pair of small craterlets lies near the mid-point.
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 lies very near the east-northeastern limb 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...
. At this location it is viewed almost from the side 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...
, and the visibility of this feature is affected by 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:...
. It lies to the north of 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"....
and northeast of the crater Cannon
Cannon (crater)
Cannon is a lunar crater that is located near the east-northeastern limb of the Moon's near side. It lies just to the northwest of the Mare Marginis, and south-southeast of the crater Plutarch. Farther to the east-northeast is Hubble....
. About one crater diameter to the north-northeast is Lyapunov
Lyapunov (crater)
Lyapunov is a lunar crater named for Aleksandr Lyapunov that is located along the east-northeastern limb of the Moon, and is viewed from the side by observers on Earth...
.
The rim of this crater is worn and eroded, and it has a somewhat irregular edge in places. The inner wall is wider along the western side, where the rim has a slight outward bulge. The most intact portion of the rim lies along the eastern side, and the inner wall of this face is visible from the Earth.
The interior floor has been resurfaced by basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
ic 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...
, giving it a lower 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...
than the surrounding terrain. It is, however, not quite as dark as the 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...
to the south. This surface is relatively level and featureless, with only a few tiny craterlets. It lacks a central peak, but a pair of small craterlets lies near the mid-point.