 Lunar Orbiter 4 image | |
| Coordinates | 15°30′S7°54′W / 15.5°S 7.9°W |
|---|---|
| Diameter | 23 km |
| Depth | 0.9 km |
| Colongitude | 8° at sunrise |
| Eponym | William Lassell |
Lassell is a small lunar impact crater that is located in the eastern part of the Mare Nubium. It was named after British astronomer William Lassell, [1] who discovered Uranian moons Ariel and Umbriel, among other achievements.
Lassell 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 polygonal 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 halfway 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.
To the west of Lassell, at coordinates 14.65°S, 350.96°E is a small highland area called the Lassell Massif, which has a reddish color relative to the surrounding mare. [2]
The massif was created by series of eruptions of viscous silicic lavas starting 4.07+0.05
−0.08 billion years ago. Its surface is suspected to be partially buried by ejecta from Copernicus crater. The southern domes Lassell G and Lassell K have most silica-rich composition and feature a caldera-like depressions on tops. [3]
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint 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 |
Eratosthenes crater is a relatively deep lunar impact crater that lies on the boundary between the Mare Imbrium and Sinus Aestuum mare regions. It forms the western terminus of the Montes Apenninus mountain range. It is named after ancient Greek astronomer Eratosthenes of Cyrene, who estimated the circumference of the Earth, and the distance from the Earth to the Sun.
Bullialdus is a lunar impact crater located in the western part of the Mare Nubium. It was named after French astronomer Ismaël Boulliau. To the north by north-west is the broken-rimmed and lava-flooded crater Lubiniezky. South-west of Bullialdus lies the smaller crater König.
Posidonius is a lunar impact crater that is located on the north-eastern edge of Mare Serenitatis, to the south of Lacus Somniorum. It was named after ancient Greek philosopher and geographer Posidonius of Apamea. The crater Chacornac is attached to the southeast rim, and to the north is Daniell.
Deslandres is the heavily worn and distorted remains of a lunar impact crater. It is located to the southeast of the Mare Nubium, in the rugged southern highlands of the Moon. In dimension it is the third-largest crater formation on the visible Moon, being beaten only by Clavius and by the 303-kilometer-diameter walled plain Bailly. The northern and eastern parts of the floor display a relatively level surface, but it is pock-marked with numerous craters. There is a small region of mare material, due to basaltic lava, along the eastern interior floor.
Grimaldi is a large basin located near the western limb of the Moon. It lies to the southwest of the Oceanus Procellarum, and southeast of the crater Riccioli. Between Oceanus Procellarum is Damoiseau, and to the north is Lohrmann.
Herodotus is a lunar impact crater located on a low shelf in the midst of the Oceanus Procellarum. To the east is the slightly larger crater Aristarchus. West across the mare is Schiaparelli. Almost due south on the mare surface is a solitary lunar dome designated Herodotus Omega (ω).
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. Alpetragius is a Latinization of the name of Nur ad-Din al-Bitruji, a Spanish-Arab astronomer.
Aristillus is a prominent lunar impact crater that lies in the eastern Mare Imbrium. It was named after Greek astronomer Aristyllus. Directly to the south is the smaller crater Autolycus, while to the southwest is the large Archimedes. To the northeast are the craters Theaetetus and Cassini.
Bessel is a small lunar impact crater that is located in the southern half of the Mare Serenitatis. The crater was named after the German astronomer Friedrich Wilhelm Bessel in 1935. Despite its small size, this is the largest crater to lie entirely within the mare. It lies to the north-northeast of the crater Menelaus.
Descartes is a heavily worn lunar impact crater that is located in the rugged south-central highlands of the Moon. To the southwest is the crater Abulfeda. It is named after the French philosopher, mathematician and physicist René Descartes.
Maraldi is a worn, eroded crater on the western edge of the Sinus Amoris, in the northeast part of the Moon. To the west-southwest is the crater Vitruvius, and to the northwest lies the worn Littrow crater. Just to the northeast of the crater is the dome-like Mons Maraldi rise.
Compton is a prominent lunar impact crater that is located in the northern hemisphere on the far side of the Moon. It lies to the east of the Mare Humboldtianum, and southwest of the walled plain Schwarzschild. To the southeast of Compton is the heavily eroded crater Swann.
Lyell is a lunar impact crater that lies along the eastern edge of the Mare Tranquillitatis, at the northern arm of the bay designated Sinus Concordiae. It was named after Scottish geologist Charles Lyell. To the north along the edge of the lunar mare is the crater Franz. The region of terrain to the east of Lyell is named Palus Somni.
Campanus is a lunar impact crater that is located on the southwestern edge of Mare Nubium. It was named after Italian astronomer Campanus of Novara. It forms a crater pair with Mercator just to the southeast. Along the southern rampart of Campanus is the small lunar mare named Palus Epidemiarum. To the southwest is the small crater Dunthorne.
Cayley is a small lunar impact crater that is located in a lava-flooded region to the west of Mare Tranquillitatis. It was named after the 19th-century English mathematician Arthur Cayley. 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.
Leibnitz is a huge lunar impact crater that is located in the southern hemisphere on the far side of the Moon. This formation is the same size as Clavius on the near side. It is located to the east-southeast of Mare Ingenii, and is joined to the northeast rim of Von Kármán. Attached to the eastern rim of Leibnitz is Davisson, and intruding into the southeast rim is Finsen. Farther to the west is the large Oppenheimer.
Denning is a lunar impact crater that is located on the far side of the Moon. It lies about midway between the craters Levi-Civita to the south and Marconi to the north-northeast. About two crater diameters to the southeast is the huge walled plain Gagarin.
Dufay is a lunar impact crater that is located on the far side of the Moon. It lies about one crater diameter to the east of the large walled plain Mandel'shtam. To the northwest is the crater Papaleksi and to the east is Valier.
Roche is a large crater on the far side of the Moon from the Earth. The prominent crater Pauli lies across the southern rim of Roche, and the outer rampart of Pauli covers a portion of Roche's interior floor. To the north-northwest of Roche is the crater Eötvös, and just to the west-northwest lies Rosseland.
