Lassell (lunar crater)
Encyclopedia
Lassell is a small lunar
crater
that is located in the eastern part of the Mare Nubium
. It lies to the west of the crater Alpetragius
, and southwest of Alphonsus
.
The interior of Lassell has been flooded and resurfaced by lava
, leaving a nearly flat surface with a low remaining outer rim. The surface has a low albedo
, giving the interior a dark appearance. The surviving outer wall is generally circular but with a somewhat polygon
al shape.
To the east-northeast is a circular, bowl-shaped crater designated Lassell B. This formation has a higher albedo than its surroundings and so appears relatively bright, especially at high sun angles.
The tiny crater Lassell D is located to the west-northwest of Lassell, about half way to the ruined crater Guericke
. This craterlet is surrounded by a patch of high-albedo
surface, and is an example of a prominent lunar bright patch. The light hue is thought to be an indication of recent formation, at least in lunar geological terms.
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 is located in the eastern part of the Mare Nubium
Mare Nubium
Mare Nubium is a lunar mare in the Nubium basin on the Moon's near side. The mare is located just to the southeast of Oceanus Procellarum. The actual basin is believed to be of Pre-Nectarian system, with the surrounding basin material being of the Lower Imbrian epoch. The mare material is of the...
. It lies to the west of the crater Alpetragius
Alpetragius (crater)
Alpetragius is a lunar impact crater located on the eastern edge of Mare Nubium, to the southwest of the much larger crater Alphonsus. In the southeast is the prominent crater Arzachel, and to the west lies the flooded Lassell....
, and southwest of Alphonsus
Alphonsus (crater)
Alphonsus is an ancient impact crater on the Moon that dates from the immediate post-Nectarian era. It is located on the lunar highlands on the eastern end of Mare Nubium, west of the Imbrian Highlands, and slightly overlaps the crater Ptolemaeus to the north. The surface is broken and irregular...
.
The interior of Lassell has been flooded and resurfaced by 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...
, leaving a nearly flat surface with a low remaining outer rim. The surface has a 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...
, giving the interior a dark appearance. The surviving outer wall is generally circular but with a somewhat polygon
Polygon
In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain orcircuit.A polygon is traditionally a plane figure that is bounded by a closed path, composed of a finite sequence of straight line segments...
al shape.
To the east-northeast is a circular, bowl-shaped crater designated Lassell B. This formation has a higher albedo than its surroundings and so appears relatively bright, especially at high sun angles.
The tiny crater Lassell D is located to the west-northwest of Lassell, about half way to the ruined crater Guericke
Guericke (crater)
Guericke is the remnant of a lunar crater at the north part of the Mare Nubium. To the north-northwest lies the large Fra Mauro formation, along with the co-joined craters Parry and Bonpland. To the east are the craters Kundt and Davy....
. This craterlet is surrounded by a patch of high-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...
surface, and is an example of a prominent lunar bright patch. The light hue is thought to be an indication of recent formation, at least in lunar geological terms.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Lassell.| Lassell | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 16.8° S | 6.8° W | 3 km |
| B | 16.1° S | 7.7° W | 4 km |
| C | 14.7° S | 9.3° W | 9 km |
| D | 14.5° S | 10.5° W | 2 km |
| E | 18.2° S | 10.2° W | 5 km |
| F | 17.1° S | 12.5° W | 5 km |
| G | 14.8° S | 9.0° W | 7 km |
| H | 14.5° S | 11.2° W | 5 km |
| J | 14.8° S | 10.4° W | 4 km |
| K | 15.1° S | 8.9° W | 4 km |
| M | 14.2° S | 8.8° W | 3 km |
| S | 18.2° S | 8.5° W | 4 km |
| T | 17.1° S | 8.8° W | 2 km |