Coordinates | 58°24′S14°24′W / 58.4°S 14.4°W Coordinates: 58°24′S14°24′W / 58.4°S 14.4°W |
---|---|
Diameter | 231 km (144 mi) |
Depth | 3.5 km (2.2 mi) |
Colongitude | 15° at sunrise |
Eponym | Christoph Klau |
Clavius is one of the largest crater formations on the Moon and the second largest crater on the visible near side (very close in size to Deslandres). It is located in the rugged southern highlands of the Moon, to the south of the prominent ray crater Tycho. It is named for the Jesuit priest Christopher Clavius.
Clavius' location toward the southern limb of the Moon causes it to appear oblong due to foreshortening. Its great size makes it visible to the unaided eye as a prominent notch in the terminator about one to two days after the Moon reaches first quarter.
It has a low outer wall in comparison to its size and is heavily worn and pock-marked by craterlets. The rim does not significantly overlook the surrounding terrain making it a "walled depression". The inner surface of the rim is hilly, notched and varies in width with the steepest portion to the south. The rim has been observed to have a somewhat polygonal outline overall.
The floor of Clavius forms a convex plain that is marked by some interesting crater impacts. The most notable of these is a curving chain of craters that begins with Rutherfurd in the south then arcs across the floor in a counterclockwise direction forming a sequence of ever diminishing diameters. From largest to smallest, these craters are designated Clavius D, C, N, J, and JA. This sequence of diminishing craters has proved a useful tool for amateur astronomers who want to test the resolution of their small telescopes.
The crater floor retains a remnant of a central massif, which lies between Clavius C and N. The relative smoothness of the floor and the low size of the central peaks may indicate that the crater surface was formed some time after the original impact.
In October 2020, NASA confirmed the existence of molecular water near Clavius, at concentrations of up to 412 parts per million. [2] The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts. [3] The water might also be sheltered between lunar soil grains. Another possibility is from very small asteroid strikes, such as a rubble pile from a much more massive "parent" asteroid collision. Pulled apart in its descent to the lunar surface similar to Comet Shoemaker–Levy 9, and hitting the surface in a modest dispersal area with a small mass at low, oblique impact angle and bouncing could allow some water to remain in the lithic matrix. The carbonaceous chondrite class is often water-rich, and the CI sub group are as much as 22% water.
Notable nearby craters include Scheiner to the west; Blancanus to the southwest; Maginus in the northeast, and Longomontanus to the northwest. The crater Rutherfurd lies entirely within the southeastern rim, while Porter overlays the northeast wall. The smaller crater Clavius L lies across the western rim while Clavius K breaks through the west-southwest rim.
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Clavius.
Clavius | Latitude | Longitude | Diameter |
---|---|---|---|
C | 57.7° S | 14.2° W | 21 km |
D | 58.8° S | 12.4° W | 28 km |
E | 51.5° S | 12.6° W | 16 km |
F | 55.4° S | 21.9° W | 7 km |
G | 52.0° S | 13.9° W | 17 km |
H | 51.9° S | 15.8° W | 34 km |
J | 58.1° S | 18.1° W | 12 km |
K | 60.4° S | 19.8° W | 20 km |
L | 58.7° S | 21.2° W | 24 km |
M | 54.8° S | 11.9° W | 44 km |
N | 57.5° S | 16.5° W | 13 km |
O | 56.8° S | 16.4° W | 4 km |
P | 57.0° S | 7.7° W | 10 km |
R | 53.1° S | 15.4° W | 7 km |
T | 60.4° S | 14.9° W | 9 km |
W | 55.8° S | 16.0° W | 6 km |
X | 60.0° S | 17.6° W | 7 km |
Y | 57.8° S | 16.0° W | 7 km |
Dawes is a lunar impact crater located in the wide straight between Mare Serenitatis and Mare Tranquilitatis. To its southwest lies the larger crater Plinius, and to its northeast sits the Mons Argaeus mountain rise. It is named after British astronomer William Rutter Dawes.
Rutherfurd is a lunar impact crater located entirely within the southern rim of the much larger crater Clavius. The crater Porter is located to the north-northeast of Rutherfurd, on the northeastern rim of Clavius. Rutherfurd forms the larger member in an arcing chain of craters of decreasing size that curves across the floor of Clavius. The craters in this chain do not appear to be the same age, so this formation is most likely random in nature.
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.
Maginus is an ancient lunar impact crater located in the southern highlands to the southeast of the prominent crater Tycho. It is a large formation almost three quarters the diameter of Clavius, which lies to the southwest. Just to the north of Maginus is the smaller crater Proctor, and to the southeast is Deluc.
Longomontanus is an ancient lunar impact crater located in the rugged southern highlands to the southwest of the bright ray crater Tycho. Longomontanus is of the variety of large lunar formations called a "walled plain", although it is actually more of a circular depression in the surface.
Scheiner is a lunar impact crater that lies to the west of the enormous walled plain Clavius. To the southeast near the rim of Clavius is the crater Blancanus. The rim of Scheiner is worn, eroded, and marked with multiple impacts. It is most heavily worn in the northern part, where a cluster of craterlets covers the entrance to a low valley leading to the north. The floor of the crater has several craterlets, including Scheiner A that lies near the midpoint. There is also a low ridge crossing part of the eastern floor.
Avogadro is an ancient lunar impact crater that is located in the northern hemisphere on the far side of the Moon. The formation has been heavily worn and eroded by subsequent impacts, so that the rim is now little more than a rounded edge surrounding the crater depression. The crater floor is equally worn, being covered in a multitude of smaller craters of various sizes. Many of these smaller craters have also been eroded, leaving little more than a faint trace on the surface.
Belʹkovich is a large lunar impact crater of the form termed a walled plain. The formation has been heavily eroded by a history of subsequent impacts, leaving it reshaped, worn, and the features softened and rounded. Belʹkovich is located along the northeastern limb of the Moon, and so its visibility is subject to libration effects. From the Earth this crater is viewed from the side, making it difficult to view it in detail.
Buch is an old, worn crater that is located in the rugged southern highlands of the Moon. It was named after German geologist Leopold von Buch. It lies to the northeast of the large crater Maurolycus, and the comparably sized crater Büsching is attached to the northeast rim.
Boole is a lunar impact crater that lies along the northwestern limb of the Moon, to the northwest of the crater Gerard. At this location it is viewed nearly from the side, and is very oblong in shape due to foreshortening. The crater formation is nearly circular, however, with a wide inner wall that has been worn and rounded due to subsequent impacts. It is named after George Boole.
Chamberlin is a lunar impact crater that is located on the far side of the Moon, just past the southeastern limb. It lies to the southeast of the crater Jeans, and Moulton is attached to the southeastern rim of Chamberlin. This crater is located in a part of the lunar surface that has undergone resurfacing of crater interiors, producing dark-hued crater floors.
Porter is a lunar impact crater that is located in the southern part of the Moon, and lies across the northeastern rim of the huge walled plain Clavius. Although generally circular, the form of this crater has been modified by the geometry of the surface on which it was formed. The outer rim is generally lower to the southwest, where it lies on the floor of Clavius. Likewise the interior floor is flatter near this face. In contrast the northeastern floor is rougher and more uneven in the northeastern half.
Casatus is a lunar impact crater that is located near the southern limb of the Moon. The north-northeast rim of the crater overlies a portion of the slightly larger crater Klaproth. Along the western rim, Casatus A intrudes somewhat into the interior, producing an inward-bowing rim. To the southeast of Casatus is Newton.
Darwin is a lunar impact crater of the type categorised as a walled plain. It lies in the southeastern part of the Moon, and is sufficiently close to the limb to appear significantly foreshortened when viewed from the Earth. Attached to its southern rim is Lamarck. To the northeast is the dark-floored crater Crüger.
d'Alembert is a large lunar impact crater located in the northern hemisphere on the far side of the Moon, to the northeast of the somewhat smaller walled plain Campbell. Astride the southwest rim of d'Alembert is Slipher. To the north is the crater Yamamoto, and to the south-southwest lies Langevin. This walled plain has the same diameter as Clavius on the near side, making it one of the largest such formations on the Moon.
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.
Cannizzaro is a lunar impact crater that is located on the Moon's far side as seen from the Earth, just beyond the northwestern limb. It lies in a region of the surface that is sometimes brought into view due to the effects of libration, but not much detail can be seen since this feature is viewed from the side. The crater lies across the southwestern rim of the much larger-walled plain Poczobutt.
Chappell is a lunar impact crater on the far side of the Moon, in the northern hemisphere just to the north of the crater Debye. It is in a heavily bombarded section of the surface, and much of its outer rim is overlain by smaller craters. The northern rim in particular has been almost completely disintegrated, while small craters also overlie the rim to the northwest and southeast. What remains of the rim forms a rounded, somewhat irregular edge to the crater depression.
Dyson is a lunar impact crater, 63 kilometers in diameter, that lies on the far side of the Moon, past the northwest limb. It is located in the northern part of the surface, to the northwest of the crater Coulomb, and east of van't Hoff.
Gruemberger is an old impact crater in the southern part of the Moon. When viewed from the Earth this crater appears oval in shape due to foreshortening, but it is actually relatively circular. The crater lies about 25 kilometers to the north-northwest of the larger and more prominent crater Moretus. The smaller crater Cysatus intrudes into the eastern rim of Gruemberger. About one and a half crater diameters to the north is the large crater Clavius.