Ramsden is a lunar impact crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 located on the western stretch of the Palus Epidemiarum

Palus Epidemiarum

Palus Epidemiarum is a small lunar mare in the southwestern part of the Moon's near side. It lies to the southwest of Mare Nubium, and southeast of Mare Humorum...

. To the east-southeast is the crater Capuanus

Capuanus (crater)

Capuanus is a lunar crater that lies along the southern edge of the Palus Epidemiarum. The outer rim is eroded and indented by lesser crater impacts, with notches in the north, west, and southern parts of the rim. The interior floor has been resurfaced by basaltic lava, which is connected to the...

, and to the north lies Dunthorne

Dunthorne (crater)

Dunthorne is a small lunar impact crater that is located to the northwest of the small lunar mare called Palus Epidemiarum, in the southwest part of the Moon's near side. It lies to the southwest of the crater Campanus, and east of Vitello. Due south is Ramsden.This crater is roughly circular and...

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The floor of the crater has been flooded with lava

Lava

Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

, and contains several small impact craters. The rim is somewhat oval and irregular in outline, with depressions at the north and south walls. It has a slight rampart, but lacks terraces, a central peak, or a ray system

Ray system

A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...

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The crater lies directly across a rille system

Rille

Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...

 named the Rimae Ramsden. These span an area 130 kilometers across, sprawling over the western Palus Epidemiarum. A branch reaches northwest to the Mare Nubium

Mare Nubium

Mare Nubium is a lunar mare in the Nubium basin on the Moon's near side. The mare is located just to the southeast of Oceanus Procellarum. The actual basin is believed to be of Pre-Nectarian system, with the surrounding basin material being of the Lower Imbrian epoch. The mare material is of the...

, passing between the craters Campanus

Campanus (crater)

Campanus is a lunar impact crater that is located on the southwestern edge of Mare Nubium. It forms a crater pair with Mercator just to the southeast. Along the southern rampart of Campanus is the small lunar mare named Palus Epidemiarum...

 and Mercator

Mercator (crater)

Mercator is a lunar crater that is located on the southwestern edge of Mare Nubium, in the southwest part of the Moon. It is located to the southeast of the crater Campanus, and the two are separated by a narrow, winding valley....

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Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Ramsden.

Ramsden	Latitude	Longitude	Diameter
A	33.4° S	31.3° W	5 km
G	35.3° S	31.6° W	11 km
H	35.7° S	32.4° W	11 km