Coordinates | 17°23′S89°41′W / 17.39°S 89.68°W Coordinates: 17°23′S89°41′W / 17.39°S 89.68°W |
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Diameter | 40.49 km |
Depth | Unknown |
Colongitude | 90° at sunrise |
Eponym | August Kopff |
Kopff is a lunar impact crater that lies along the eastern edge of the inner Mare Orientale impact basin, on the western limb of the Moon. In this position the crater is seen from on edge from the Earth, and its visibility is affected by libration. This situation makes it difficult to discern much detail about the crater unless it is viewed from orbit.
At one time this crater was considered to have formed due to volcanic activity, [1] in contrast to most lunar craters which are considered to have been created through impacts. However it is more likely that the crater was formed by an impact against a surface that was still partly molten. This has left the crater with a sharp-edged, circular rim and a flat, dark-hued interior floor. Indeed, the albedo of the interior floor matches that of the lunar mare to the west. The southeast part of the floor is fractured with a series of narrow rilles. The floor along the northwest and northeast edges is more rugged, and these sections have escaped the lava that covered the remainder of the floor.
The crater was named after German astronomer August Kopff by the IAU in 1970. [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 Kopff.
Kopff | Latitude | Longitude | Diameter |
---|---|---|---|
B | 16.9° S | 86.2° W | 8 km |
C | 18.3° S | 86.1° W | 14 km |
D | 19.9° S | 89.8° W | 13 km |
E | 16.0° S | 89.8° W | 12 km |
The following craters have been renamed by the IAU.
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.
Acosta is a small lunar impact crater located just to the north of the prominent crater Langrenus, near the east edge of Mare Fecunditatis. To the west are the trio of Atwood, Naonobu, and Bilharz. Acosta is named after the Portuguese naturalist Cristóvão da Costa.
Avery is a small lunar impact crater located near the eastern limb of the Moon. This is a circular, bowl-shaped formation with a small interior floor. It lies near the western edge of Mare Smythii. To the east is the crater Haldane, and to the southwest is Carrillo. Gilbert lies to the southwest.
Egede is the remains of a lunar impact crater that has been flooded by lava, leaving only the somewhat polygonal circumference of the rim protruding just above the mare. It was named after Dano-Norwegian natural historian Hans Egede. It is located on the southern edge of the Mare Frigoris, to the west of the crater Aristoteles. To the southwest is an arc of low mountains curving between the rims of Aristoteles and Eudoxus. The floor of Egede is flat and nearly featureless, except for a few tiny craterlets, including secondaries from Aristoteles. The surviving rim has a maximum altitude of 0.4 km above the surface.
Schiaparelli is a lunar impact crater located on the western part of the Oceanus Procellarum, to the west of the crater Herodotus. The rim is relatively sharp-edged and relatively free from impact wear. The inner walls have slumped to form a shelf around much of the sides. The interior floor is somewhat irregular, but free from impacts of note.
Endymion is a lunar impact crater that lies near the northeast limb of the Moon. It is located to the east of Mare Frigoris and north of Lacus Temporis. To the southwest is the somewhat smaller crater Atlas. Because of its location, Endymion has an oval appearance from foreshortening. Beyond the crater along the lunar limb is the Mare Humboldtianum.
Hohmann is a lunar impact crater that lies within the central basin of the Mare Orientale formation, on the farside of the Moon. It is located to the south of the crater Maunder, and to the west of Kopff crater. Due to its proximity to the western lunar limb, this area of the surface is occasionally visible during favorable librations. However the basin is viewed from the side, restricting the amount of detail that can be observed from Earth.
Encke is a lunar impact crater that is located on the western edge of the Mare Insularum, to the south-southeast of the crater Kepler. The small crater Kunowsky lies to the east-southeast on the mare.
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.
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.
Keldysh is a lunar impact crater that is located in the northeastern part of the Moon, at the eastern rim of the Mare Frigoris. It lies due north of the prominent crater Atlas, and to the northeast of the notable Hercules.
Maunder is a lunar impact crater that is located on the far side of the Moon, just beyond the western limb. This region is sometimes brought into view during favorable librations, but not much detail can be seen. The crater lies at the northern end of the Mare Orientale, within the ring of mountains named Montes Rook, and it is the largest crater on this lunar mare. To the southeast is the crater Kopff, and due south is the small Hohmann.
Lallemand is a small lunar impact crater that lies near the western limb of the Moon, in a region where the visibility is affected by libration effects. Because of its location, when viewed from the Earth the crater is viewed nearly from the side, limiting the amount of detail that can be seen. It lies in the northeast part of a mountain range named the Montes Rook that forms a ring around the enormous Mare Orientale impact basin. To the northeast is the Lacus Autumni and to the northwest lies the Lacus Veris, both forming small lunar maria along the sides of the range.
Couder is a small lunar impact crater that is located just behind the western limb of the Moon, in a region of the surface that is brought into view during favorable librations. It lies on the inner foothills of the Montes Cordillera, a ring-shaped mountain range that surrounds the Mare Orientale impact basin.
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.
Kao is a small lunar impact crater that is located near the eastern limb of the Moon. It lies near the southern edge of the Mare Smythii, a lunar mare that continues onto the far side of the surface. This crater lies to the east-southeast of the crater Widmannstätten. Less than a crater diameter to the north-northeast is the small crater Tucker.
Chalonge is a lunar impact crater that is located on the far side of the Moon. It lies to the southwest of the larger crater Lewis, in the outer skirt of ejecta that surrounds the Mare Orientale impact basin. To the southeast are the Montes Cordillera, a ring of mountains that encircle the Mare Orientale formation.
Konstantinov is a lunar impact crater that is located to the southeast of the Mare Moscoviense, on the far side of the Moon. To the west of Konstantinov is the smaller crater Nagaoka, and to the south-southeast is the small Van Gent.
Leonov is a small lunar impact crater that lies to the south of Mare Moscoviense, one of the few maria on the far side of the Moon. This crater has a heart-shaped outline, due to an outward bulge along the northwest side. The rim of Leonov is worn, and several tiny craterlets lie along the edge. The inner walls and interior floor are relatively featureless.
Meitner is an impact crater on the far side of the Moon, behind the eastern limb. It lies to the northwest of the crater Kondratyuk, and about a crater diameter to the west of Langemak.