Coordinates | 18°12′S1°54′W / 18.2°S 1.9°W |
---|---|
Diameter | 96 km |
Depth | 3.6 km |
Colongitude | 3° at sunrise |
Eponym | Abū Ishāq Ibrāhīm al-Zarqālī |
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 (the visible center of the Moon). 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.
Arzachel is remarkably clear in its structure and a favorite telescope viewing subject for advanced amateur astronomers. The rim of Arzachel shows little sign of wear and has a detailed terrace structure on the interior, especially on the slightly higher eastern rim. There is a rough outer rampart that joins a ridge running from the north rim to southern rim of Alphonsus.
The rugged central peak of Arzachel is prominent, rising 1.5 kilometers above the floor, and is somewhat offset to the west with a bowed curve from south to north-northeast. The floor is relatively flat, except for some irregularities in the southwestern quadrant of the crater. There is a rille system named the Rimae Arzachel that runs from the northern wall to the southeast rim. A small crater lies prominently in the floor to the east of the central peak, with a pair of smaller craterlets located nearby.
Arzachel is a Latinization of the name of the Arab astronomer and mathematician Abū Ishāq Ibrāhīm al-Zarqālī. [2] Like many of the craters on the Moon's near side, Arzachel was named by Giovanni Riccioli, whose 1651 nomenclature system has become standardized. [3] Earlier lunar cartographers had given the feature different names: Michael van Langren's 1645 map calls it "Annae, Reg. Fran.", after Anne, the Regent of France, [4] and Johannes Hevelius called it "Mons Cragus" after one of the Mount Craguses of the ancient world. [5]
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Arzachel.
Arzachel | Latitude | Longitude | Diameter |
---|---|---|---|
A | 18.0° S | 1.5° W | 10 km |
B | 17.0° S | 2.9° W | 8 km |
C | 17.4° S | 3.7° W | 6 km |
D | 20.2° S | 2.1° W | 8 km |
H | 18.7° S | 2.0° W | 5 km |
K | 18.3° S | 1.6° W | 4 km |
L | 20.0° S | 0.1° E | 8 km |
M | 20.6° S | 0.9° W | 3 km |
N | 20.4° S | 2.2° W | 3 km |
T | 17.7° S | 1.3° W | 3 km |
Y | 18.2° S | 4.3° W | 4 km |
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.
Albategnius is an ancient lunar impact crater located in the central highlands. It is named after the Mesopotamian Muslim astronomer and scientist Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī, Latinized as Albategnius.
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.
Ammonius is a bowl-shaped lunar impact crater with a slightly raised rim. It is located on the floor of the walled plain Ptolemaeus, about 30 kilometers northeast of the crater midpoint.
Ptolemaeus is an ancient lunar impact crater close to the center of the near side, named for Claudius Ptolemy, the Greco-Roman writer, mathematician, astronomer, geographer and astrologer. It measures approximately 154 kilometers in diameter.
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.
Thebit is a lunar impact crater located on the southeast shore of Mare Nubium. To the north-northwest is the crater Arzachel, and Purbach lies to the south-southwest. To the southwest is the flooded remnants of Thebit P, which is actually larger in diameter than Thebit itself.
Wallace is the remains of a lunar impact crater that has been flooded by lava. It was named after British natural historian Alfred Russel Wallace. It lies in the southeastern part of Mare Imbrium, to the northeast of the crater Eratosthenes. The crater rim forms a somewhat polygonal outline, and is broken in the southeast. The floor is flat and devoid of significant features, but it is overlain by ray material from Copernicus to the southwest. The rim ascends to an altitude of 0.4 km above the lunar mare.
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.
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.
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.
Arago is a lunar impact crater located in the western part of the Mare Tranquillitatis. It was named after French astronomer François Arago in 1935. Its diameter is 26 km. To the southwest lies the crater Manners, and beyond are Dionysius and the Ritter–Sabine crater pair. To the southeast is the large Lamont formation that has been submerged by the mare.
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.
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.
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.
Manilius is a lunar impact crater on the northeast edge of Mare Vaporum. Its diameter is 38 km.
Bianchini is a lunar impact crater that lies along the northern Jura Mountains that ring the Sinus Iridum, in the northwestern part of the near side of the Moon. It was named after Italian astronomer Francesco Bianchini. The impact of this crater near the edge of the Jura Mountains deposited some material into the Sinus Iridum floor.
Azophi is a lunar impact crater that lies in the rugged south-central highlands of the Moon. The crater is named after the 10th-century Persian astronomer Abd Al-Rahman Al Sufi, also known by his western name, Azophi. The northwest rim is attached to the slightly smaller crater Abenezra, to the east-southeast is the large and irregular Sacrobosco, and to the west-southwest is Playfair.
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.
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.