Coordinates | 17°33′S39°58′W / 17.55°S 39.96°W |
---|---|
Diameter | 110 km |
Depth | 1.9 km |
Colongitude | 40° at sunrise |
Eponym | Pierre Gassendi |
Gassendi is a large lunar impact crater feature located at the northern edge of Mare Humorum. It was named after French astronomer Pierre Gassendi. [1] The formation has been inundated by lava during the formation of the mare, so only the rim and the multiple central peaks remain above the surface. The outer rim is worn and eroded, although it retains a generally circular form. A smaller crater – Gassendi A – intrudes into the northern rim, and joins a rough uplift at the northwest part of the floor. The crater pair bear a curious resemblance to a diamond ring.
In the southern part of the crater floor is a semi-circular ridge-like formation that is concentric with the outer rim. It is in the southern part where the rim dips down to its lowest portion, and a gap appears at the most southern point. The rim varies in height from as little as 200 meters to as high as 2.5 kilometers above the surface. The floor has numerous hummocks and rough spots. There is also a system of rilles that criss-crosses the floor, named the Rimae Gassendi.
The fresh crater Gassendi A is adjacent to Gassendi to the north. Due to its ray system, Gassendi A is mapped as part of the Copernican System. [2] On some older maps the crater Gassendi A was called Clarkson, after the British amateur astronomer and selenographer Roland L. T. Clarkson, but this name is not officially recognized by the IAU and the name has been removed.
Gassendi was considered for a possible landing site during the Apollo program, but was never selected. However, it was imaged at high resolution by Lunar Orbiter 5, for this reason. It was also heavily photographed by Apollo 16.
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Gassendi.
Alphonsus is an ancient impact crater on the Moon that dates from the pre-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. To the southwest is the smaller Alpetragius. The crater name was approved by the IAU in 1935.
Copernicus is a lunar impact crater located in eastern Oceanus Procellarum. It was named after the astronomer Nicolaus Copernicus. It typifies craters that formed during the Copernican period in that it has a prominent ray system. It may have been created by debris from the breakup of the parent body of asteroid 495 Eulalia 800 million years ago.
Arzachel is a relatively young lunar impact crater located in the highlands in the south-central part of the visible Moon, close to the zero meridian. It lies to the south of the crater Alphonsus, and together with Ptolemaeus further north the three form a prominent line of craters to the east of Mare Nubium. The smaller Alpetragius lies to the northwest, and Thebit is to the southwest along the edge of the mare.
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.
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.
Hipparchus is the degraded remnant of a lunar impact crater. It was named after the Greek astronomer, geographer and mathematician Hipparchus. It is located to the southeast of Sinus Medii, near the center of the visible Moon. To the south is the prominent crater Albategnius, and to the southwest lies Ptolemaeus, a feature of comparable dimensions to Hipparchus. Horrocks lies entirely within the northeast rim of the crater. Halley is attached to the south rim, and Hind lies to the southeast. To the north-northeast is the bowl-shaped Pickering, and the flooded Saunder is located off the northeast rim. High-resolution images of Hipparchus were obtained by Lunar Orbiter 5 in 1967.
Petavius is a large lunar impact crater located to the southeast of the Mare Fecunditatis, near the southeastern lunar limb. Attached to the northwest rim is the smaller crater Wrottesley. To the southeast are Palitzsch, Vallis Palitzsch, and Hase. Farther to the north is the large crater Vendelinus. Petavius appears oblong when viewed from the Earth due to foreshortening. Petavius is Imbrian in age.
Burnham is a small crater located to the southeast of the crater Albategnius, in a relatively smooth area of the lunar surface. It was named after American astronomer Sherburne W. Burnham. To the southwest is Vogel.
Taruntius is a lunar impact crater on the northwestern edge of Mare Fecunditatis. It was named after ancient Roman philosopher, mathematician and astrologer Lucius Tarutius Firmanus. To the northwest is the lava-flooded crater Lawrence, and to the north lie the craters Watts and da Vinci.
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.
Dionysius is a lunar impact crater that lies on the western edge of the Mare Tranquillitatis. It was named after Dionysius the Areopagite. To the southeast is the crater pair of Ritter and Sabine. Just to the northwest is the system of rilles designated Rimae Ritter. These clefts follow a generally northwest direction.
Gambart is a small lunar impact crater on the Mare Insularum, near the central region of the Moon. It is named after French astronomer Jean-Félix Adolphe Gambart. It can be located to the south-southeast of the prominent ray crater Copernicus. In the past, the floor of Gambart has been flooded with lava, leaving a relatively flat surface surrounded by a smooth but somewhat polygon-shaped outer rim. To the southwest of Gambart is an area of hilly terrain deposited from ejecta during the Mare Imbrium impact, known as the Fra Mauro Formation.
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.
Godin is a lunar impact crater located just to the south of the crater Agrippa, on a rough upland region to the east of Sinus Medii. Its diameter is 34 km. The crater was named after 18th century French astronomer Louis Godin. The ruined crater Tempel lies to the northeast, on the east side of Agrippa. Due south is the flooded remains of Lade.
King is a prominent lunar impact crater that is located on the far side of the Moon, and can not be viewed directly from Earth. The crater was named after Arthur Scott King and Edward Skinner King in 1970. Prior to that, this crater was known as Crater 211. It forms a pair with Ibn Firnas, which is only slightly larger and is attached to the northeast rim of King. To the northwest is the crater Lobachevskiy, and Guyot is located an equal distance to the north-northwest.
Davy is a small lunar impact crater that is located on the eastern edge of the Mare Nubium. It was named after British physicist Humphry Davy. It overlies the lava-flooded remains of the satellite crater Davy Y to the east, a formation which contains a crater chain designated Catena Davy. To the southeast of Davy is the prominent crater Alphonsus.
Gardner is a small lunar impact crater in the northeast part of the Moon and is named after an American physicist Irvine Clifton Gardner. It lies due east of the crater Vitruvius, in a section of rough terrain north of the Mare Tranquillitatis. Gardner was previously designated Vitruvius A before being given its present name by the IAU. To the northeast of Gardner is the larger crater Maraldi.
Mendeleev is a large lunar impact crater that is located on the far side of the Moon, as seen from the Earth. The southern rim of this walled plain just crosses the lunar equator. Intruding into the eastern rim of Mendeleev is the crater Schuster. Nearly on the opposite side, the smaller Hartmann intrudes into west-southwestern rim.
Lavoisier is a lunar impact crater that is located near the northwestern limb of the Moon, at the western edge of the Oceanus Procellarum. It is named after the French chemist Antoine Lavoisier. It is located to the southwest of the crater von Braun and southeast of Bunsen. Due south of Lavoisier is the disintegrated crater Ulugh Beigh.
Necho is a lunar impact crater on the far side of the Moon, and therefore cannot be seen directly from the Earth. It lies to the northeast of the larger crater Langemak, about a crater diameter to the south-southwest of Bečvář and further east is Love.