Elger is 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 lies along the southern edge of

Palus Epidemiarum Palus Epidemiarum (Latin ''palūs epidēmiārum'' ''Marsh of Epidemics'') is a small lunar mare in the southwestern part of the Moon's near side. This feature forms a rough band of lava-flooded terrain that runs generally west–east, with a nor ...

, the Marsh of Epidemics, in the southwest part 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 ...

's near side. To the northeast is the flooded crater Capuanus, and farther to the northwest is

Ramsden Ramsden may refer to: ;Places: *Ramsden, Orpington, England *Ramsden, Oxfordshire, England, a village and civil parish *Ramsden, Worcestershire, England, a hamlet *Ramsden Park, Toronto, Canada *Ramsden (crater), on the Moon *8001 Ramsden, an aste ...

. The crater is named after British astronomer

Thomas Gwyn Elger Thomas Gwyn Empy Elger FRAS (27 October 1836 – 9 January 1897) was a British selenographer and one of the preeminent lunar observers of the Victorian age, best known for his lunar map, which was regarded as one of the best available until ...

. The rim of this formation is rough and somewhat eroded formation, with a break and an outward bulge along the northern end, while a ridge intrudes into the southern rim. The interior has been resurfaced by

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 ...

, although the

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...

of the floor is not quite as low as the

lunar mare The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

surface to the north.

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 Elger.

References

* * * * * * * * * * * {{Craters on the Moon: C-F Impact craters on the Moon