Coordinates | 66°48′S69°24′W / 66.8°S 69.4°W |
---|---|
Diameter | 303 km (188 mi) |
Depth | 4.3 km (2.7 mi) |
Colongitude | 65° at sunrise |
Eponym | Jean S. Bailly |
Bailly is a lunar impact crater that is located near the south-west limb of the Moon. It was named after French astronomer Jean S. Bailly. [1] The oblique viewing angle gives the crater a foreshortened appearance, and the location near the limb can limit visibility due to libration. The most favorable time for viewing this feature is near the full moon when the terminator is crossing the crater wall.
This is the largest crater on the near side of the Moon. In area it is comparable in size to a small mare. It lies north of the crater Le Gentil and east of Hausen. Further west of Bailly are the (unofficially named) Montes Dörfel mountains.
Bailly's uneven crater floor has remained free of lava flooding, and it is covered with a multitude of ridges and craters. The entire crater has been battered and worn, and the outer ramparts are eroded and in some places have even been worn away by myriad impacts. If the crater ever possessed a central peak, it is no longer discernible. Due to its current condition, observers have termed this feature a 'field of ruins'.
Due to the size and the worn state of this crater, it is estimated to be more than 3 billion years old, and is part of the Nectarian system. [2]
The south-eastern part of the crater is home to two notable craters, designated Bailly A and Bailly B. These craters overlap, and Bailly A lies across the rim of Bailly's mountainous wall. Selenographer Giovanni Battista Riccioli named Bailly B, Bartolus for fellow Ferrarese Jesuit Daniello Bartoli (1608-1685) in his Almagestum novum (1651). [3] The name was not recognized by the IAU.
Anaximenes is a low-rimmed lunar impact crater near the north-northwest limb of the Moon. It lies to the west of the crater Philolaus, and northeast of Carpenter. To the northwest is Poncelet, close to the visible edge of the Moon.
Bettinus is a lunar impact crater located near the southwest limb. Due to its location, the crater has a distinctly oval shape because of foreshortening. To the south of the rim is the similar-sized crater Kircher, and to the northwest is the slightly smaller Zucchius. From the west to the southwest, closer to the limb, is the giant formation Bailly.
Segner is a lunar impact crater located near the southwestern limb of the Moon, to the northeast of the giant walled plain Bailly. The crater Zucchius is a few kilometers to the south-southwest of the rim, and to the north east lies the unusual formation Schiller. The smaller crater Weigel is located to the east.
Carrillo is a small lunar impact crater located near the eastern limb of the Moon. In this location the crater is subject to lunar libration effects, and appears highly oval due to foreshortening. It is located on the slope of highlands on the west side of Mare Smythii, and its inner wall is wider on the western side than to the east.
Boguslawsky is a lunar impact crater that is located near the southern lunar limb, to the northwest of the slightly larger crater Demonax, and southwest of the concentric crater Boussingault. Due to its location, this crater appears very oblong in shape because of foreshortening.
Byrgius is a lunar impact crater located in the western part of the Moon, near the limb. As a result, Byrgius appears strongly oval in shape due to foreshortening. To the northwest is the nearly ruined crater Lamarck. The rim of Byrgius is worn and eroded, with Byrgius A overlying the eastern rim and Byrgius D lying across the northwest. The floor is relatively flat and undistinguished by significant craters. Byrgius A possesses its own ray system that extends for over 400 kilometres.
Ansgarius is a lunar impact crater that is located near the eastern limb of the Moon. When viewed from the Earth, the crater has a highly oval shape due to foreshortening, but the rim is actually nearly circular. To the northwest of Ansgarius is the crater La Pérouse, and south is Behaim.
Arnold is a lunar impact crater that is located in the north-northeastern part of the visible Moon, near the lunar limb. This location gives the crater a notably oval appearance due to foreshortening, although the formation is actually relatively round. It lies to the northeast of the Mare Frigoris, to the north of the crater Democritus. West of Arnold is the smaller crater Moigno.
Arrhenius is a lunar impact crater that is located just on the far side of the Moon, near the southwest limb. In this location the vicinity of the crater can be viewed during favorable librations, although it is viewed from on edge. To the south-southeast is the worn crater Blanchard, and De Roy lies further to the west.
Back is a small lunar impact crater that is located near the eastern limb of the Moon. It lies on the northwest edge of the Mare Smythii, and the northeast rim is adjacent to the crater Schubert. To the west is Jenkins, and to the southwest is the Weierstrass–Van Vleck crater pair.
Balboa is a lunar impact crater that is located near the western limb of the Moon. Due to foreshortening, the crater appears highly oval when viewed from the Earth. In actuality, however, the formation is relatively circular. It is comparable in size to the crater Dalton, located just to the southwest. The eastern rim of Balboa lies just to the west of the Oceanus Procellarum.
Beals is a lunar impact crater that is located near the eastern limb of the Moon, and lies across the southwestern rim of the crater Riemann. From the Earth the crater is viewed nearly from on edge, and is best seen during favorable librations. To the west is the large walled plain Gauss.
Behaim is a lunar impact crater that is located near the eastern limb of the Moon, just to the south of the crater Ansgarius. To the south of Behaim is the crater Hecataeus, and to the east-southeast is Gibbs.
Bohr is a lunar impact crater that is located near the western lunar limb, in the area that is affected by librations. It is attached to the southwestern rim of the larger, eroded Vasco da Gama formation, and to the southeast of the crater Einstein. The crater was observed for the first time in 1963, by Arthus and Ewen Whitaker in the book Rectified Lunar Atlas.
Pingré is a lunar impact crater that is located near the southwest limb of the Moon, beyond the large crater Phocylides. It lies to the northwest of the huge walled basin Bailly, and to the east of the smaller Graff. Due to its location, this crater appears foreshortened when viewed from the Earth.
Boussingault is a large lunar impact crater that lies near the rugged southeast limb of the Moon. Because of its location, Boussingault appears highly oblong in shape due to foreshortening. To the southwest is the crater Boguslawsky, and almost attached to the northeast rim is Helmholtz. East-southeast of Boussingault lies the crater Neumayer.
Cannon is a lunar impact crater that is located near the east-northeastern limb of the Moon's near side. It lies just to the northwest of the Mare Marginis, and south-southeast of the crater Plutarch. Farther to the east-northeast is Hubble.
Demonax is a lunar impact crater near the southern limb of the Moon. This location makes the crater difficult to observe due to foreshortening. The crater is also illuminated at a very low angle, when it is in the sunlit side. Demonax lies just to the north of the crater Scott, one of the south polar formations. To the north-northwest is Boguslawsky.
Le Gentil is a lunar impact crater that is located in the south-southwest part of the Moon, near the limb, and is nearly attached to the southern rim of the huge walled plain Bailly. To the southeast is the large crater Drygalski. Due to its location, this crater appears considerably foreshortened and is viewed from an oblique angle by observers on the Earth.
Kapteyn is a lunar impact crater that is near the eastern limb of the Moon, to the west of the crater La Pérouse. West of Kapteyn is the slightly smaller Barkla, and farther to the west-northwest is the prominent Langrenus. Von Behring is to the north-northeast.