Coordinates | 21°48′N17°54′E / 21.8°N 17.9°E |
---|---|
Diameter | 16 km |
Depth | 1.7 km |
Colongitude | 342° at sunrise |
Eponym | Friedrich W. Bessel |
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. [1] 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.
This crater is circular and bowl-shaped with a rim that has a higher albedo than the floor or the surrounding mare. The outer rim is not significantly worn, and there are no features of note on the interior, apart from some slumping of material from the inner walls to the floor. Bessel is not of sufficient size to have developed the terrace structures of larger craters.
A large ray crosses the mare from north to south, passing Bessel's western side. This ray is enigmatic due to its unclear origin. It appears to originate at the rim of Menelaus crater, yet it aligns with the trajectory of a Tycho ray, suggesting Tycho as a possible source. However, the Tycho ray terminates in the central highlands, hundreds of kilometers south of the Bessel region. Additionally, there are no evident clusters of Tycho secondary craters along the ray between its end in the highlands and the start of the bright ray at Menelaus' rim. [2]
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Bessel.
Bessel | Latitude | Longitude | Diameter |
---|---|---|---|
D | 27.3° N | 19.9° E | 5 km |
F | 21.2° N | 13.8° E | 1 km |
G | 21.1° N | 14.7° E | 1 km |
H | 25.7° N | 20.0° E | 4 km |
The following craters have been renamed by the IAU:
Menelaus is a young lunar impact crater located on the southern shore of Mare Serenitatis near the eastern end of the Montes Hæmus mountain range. Its diameter is 27 km. To the southwest is the small crater Auwers, and to the west-southwest is the even smaller Daubrée. To the northeast is a faint rille system named the Rimae Menelaus.
Bobillier is a tiny, cup-shaped lunar impact crater in the southwest part of Mare Serenitatis. It was named after French geometer Étienne Bobillier in 1976. It lies to the north-northwest of the crater Bessel. To the south and west is a wrinkle ridge designated Dorsum Buckland. Bobillier was previously identified as Bessel E.
Finsch is a relatively small lunar impact crater in the mid-part of Mare Serenitatis that has been almost completely covered by the mare, forming a ghost crater in the lava plain. It was named after German zoologist Otto Finsch. It is located to the south-southeast of the crater Sarabhai and northeast of Bessel.
Kies is the remnant of a lunar impact crater that has been flooded by basaltic lava, leaving only a remnant of the outer rim. It was named after German mathematician and astronomer Johann Kies. It is located in the Mare Nubium almost due south of the crater Bullialdus. Northwest of Kies is König. To the south-southwest lies a lunar dome structure designated Kies Pi (π). It has a small crater at the top and is most likely volcanic in origin.
Stöfler is a large lunar impact crater located in the crater-dotted southern highlands. It was named after 15th-16th century German astronomer and mathematician Johannes Stöffler. It sits to the west of the crater Maurolycus. The distorted crater Fernelius is attached to the northern rim, and Miller and Nasireddin lie to the west. Faraday has overlain and damaged the western rim, and this crater in turn has been overlain by several smaller craters.
Polybius is a lunar impact crater in the southeast part of the Moon, and is named after ancient Greek historian Polybius. It is located to the south-southeast of the larger crater Catharina, in the area framed by the Rupes Altai scarp. Some distance to the northeast is the Mare Nectaris, with the flooded craters Beaumont and Fracastorius.
Orontius is a lunar impact crater that lies in the heavily cratered southern highlands of the Moon's near side. It was named after 16th century French mathematician Oronce Fine. It is located to the northwest of the prominent ray crater Tycho, and south and east of the large walled plain Deslandres. The eastern part of the crater is overlain by the smaller crater Huggins, which is overlain in turn on its eastern rim by the still smaller Nasireddin, the trio forming a crater chain of diminishing dimensions. Joined to the southern rim is the crater Saussure. To the southwest, just east of Tycho, is Pictet.
Kepler is a lunar impact crater that lies between the Oceanus Procellarum to the west and Mare Insularum in the east. To the southeast is the crater Encke. Kepler is named for the 17th century German astronomer and mathematician Johannes Kepler.
La Caille is a lunar impact crater located in the rugged south-central highlands of the Moon. It was named after the French astronomer Nicolas-Louis de Lacaille. It is located to the northeast of the crater Purbach. Nearly attached to the southeast rim are the remains of Blanchinus, and the two are separated by a rugged stretch of terrain. To the northeast is Delaunay, a formation split in half by a ridge.
Auwers is a small lunar impact crater located in the Montes Haemus mountain range at the south edge of Mare Serenitatis. It is named after German astronomer Arthur Auwers. It lies southeast of the crater Menelaus. The irregular rim of Auwers has a gap at the north-northwest edge, which allowed lava flows to reach the crater floor and flood the interior.
Fechner is a lunar impact crater that lies on the far side of the Moon's southern hemisphere, attached to the western rim of the large walled plain Planck. The eastern rim of Fechner intersects the Vallis Planck, a long, wide cleft in the surface that follows a course to the north-northwest. This valley intrudes into the southeastern rim of the crater, then continues northwards from the periphery of the northeast rim.
Ball is a lunar impact crater that is located in the rugged southern highlands of the Moon. It was named after British astronomer William Ball. The formation is circular and symmetrical, and has received little significant wear. The interior is rough-surfaced, curving downward toward the relatively wide central peak at the midpoint.
Daubrée is a lunar impact crater that is located to the southwest of the Mare Serenitatis, just to the west-southwest of the crater Menelaus in the Montes Haemus range. The small lunar mare Lacus Hiemalis lies along the southwest rim of Daubrée. The crater was named after French geologist Gabriel A. Daubrée. It was previously designated Menelaus S.
Wilhelm is a lunar impact crater in the southern part of the Moon, to the west of the prominent Tycho. Portions of the ray material from Tycho lie across the rim and floor of Wilhelm. Attached to its southern rim is the crater Montanari, while Lagalla is attached to the southwest. To the north-northeast is Heinsius.
Cichus is a lunar impact crater that lies in the southwestern part of the Moon, at the eastern edge of Palus Epidemiarum. Just to the northeast and nearly contacting the rim is the lava-flooded crater remnant Weiss. The crater is named after Italian astronomer Cecco d'Ascoli.
Montanari is a lunar impact crater. It is located to the west-southwest of the prominent ray crater Tycho, and is attached to the southern rim of the walled plain Wilhelm. Along the northwestern side is the crater remnant Lagalla, and just to the south is the large walled plain Longomontanus.
Weiss is a lunar impact crater along the southern edge of the Mare Nubium. It was named after Austrian astronomer Edmund Weiss. Nearly attached to the southwest rim is the crater Cichus, and Pitatus lies just over one crater diameter to the east-northeast. To the east-southeast lies the eroded Wurzelbauer.
Goodacre is a lunar impact crater. It is located in the rugged southern highlands on the Moon's near side, and is attached to the north-northeastern part of the exterior of Gemma Frisius, a heavily worn and much larger formation. About two crater diameters to the north of Goodacre lies Pontanus.
Helmert is a lunar impact crater at the southern edge of the Mare Smythii. It lies near the eastern limb of the Moon, and from the Earth it is seen nearly from the side. The visibility of this feature can be strongly affected by libration of the Moon in its orbit.
Mandelʹshtam is the remains of a large crater on the Moon's far side named after Leonid Mandelstam. Nearly attached to the northeast outer rim is the crater Papaleksi. To the south lies the crater Vening Meinesz.