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 circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

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 Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to Science * Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon * ...

of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. Its diameter is 41 km. It was named after the

Austrian Austrian may refer to: * Austrians, someone from Austria or of Austrian descent ** Someone who is considered an Austrian citizen, see Austrian nationality law * Austrian German dialect * Something associated with the country Austria, for example: ...

astronomer

Theodor von Oppolzer Theodor von Oppolzer (26 October 1841 – 26 December 1886) was an Austrian Empire, Austrian astronomer and mathematician of Bohemia, Bohemian origin. The son of the physician Johann Ritter von Oppolzer, Theodor was born in Prague. He completed h ...

. 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 moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

-flooded walled plain

Flammarion Flammarion may refer to: * Camille Flammarion (1842–1925), French astronomer and author * Gabrielle Renaudot Flammarion (1877–1962), French astronomer, wife of Camille Flammarion * Flammarion engraving by unknown artist; appeared in a book by C ...

. 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 wid ...

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

{{Commonscat
Oppolzer at The Moon Wiki
Impact craters on the Moon