Oppolzer is the remnant of a

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

that is located on the southern edge of

Sinus Medii Sinus Medii (Latin ''sinus mediī'' "Middle Bay") is a small lunar mare. It takes its name from its location at the intersection of the Moon's equator and prime meridian; as seen from the Earth, this feature is located in the central part of the ...

, along the meridian of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

. Its diameter is 41 km. It was named after the Austrian astronomer Theodor von Oppolzer. It is located within one crater diameter of the origin of the selenographic coordinate system at 0° N, 0° W. Attached to the surviving remnants of the southeast rim is the crater Réaumur. To the west-southwest is the

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

-flooded walled plain

Flammarion Flammarion may refer to: * Camille Flammarion (1842–1925), French astronomer and author * Gabrielle Renaudot Flammarion (1877–1962), French astronomer, second wife of Camille Flammarion * Sylvie Flammarion (1836-1919), French feminist and paci ...

. This formation consists of little more than an irregular arc of mounts along the south, and a ring of scattered ridges along the northern rim. There is a particularly wide gap in the rim to the northeast where no ridges survive to mark the crater perimeter. The interior floor has been resurfaced by

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

. A 110-km-long

rille Rille (German for 'groove') is typically used to describe any of the long, narrow depressions in the surface of the Moon that resemble channels. The Latin term is ''rima'', plural ''rimae''. Typically, a rille can be several kilometers w ...

designated Rima Oppolzer passes through the southern part of the crater floor, and continues to the east and west of the crater.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Oppolzer. Oppolzer crater AS16-M-0842

References

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External links

{{Commons category
Oppolzer at The Moon Wiki
Impact craters on the Moon