Horrocks is a lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 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 entirely within the eroded northeast rim of the much larger walled plain Hipparchus

Hipparchus (lunar crater)

Hipparchus is the degraded remnant of a lunar crater. It is located to the southeast of Sinus Medii, near the center of the visible Moon. To the south is the prominent crater Albategnius, and to the southwest lies Ptolemaeus, a feature of comparable dimensions to Hipparchus. Horrocks lies entirely...

. To the south of Horrocks are the craters Halley

Halley (lunar crater)

Halley is a lunar impact crater that is intruding into the southern wall of the walled plain Hipparchus. To the southwest of Halley is the large crater Albategnius, and due east lies the slightly smaller Hind....

 and Hind

Hind (crater)

Hind is a lunar impact crater that lies to the southeast of the walled plain Hipparchus, and due east of the crater Halley. The rim of Hind is relatively free of wear and distortion, except for a break at the north rim. The floor of Hind is relatively uneven, however, compared to the interior of...

 and Rhaeticus

Rhaeticus (crater)

Rhaeticus is a lunar crater that lies astride the equator of the Moon, on the southeast edge of the Sinus Medii. To the north-northwest is the crater Triesnecker, and due south can be found the worn remnant of the walled plain Hipparchus...

 to the north. Gyldén

Gyldén (crater)

Gyldén is the remnant of a lunar crater that is located to the northeast of the walled plain Ptolemaeus on the Moon. It lies along the prime meridian of the selenographic coordinate system, and less than 150 km south of the lunar equator...

 and Saunder

Saunder (crater)

Saunder is a lunar crater located in the central highland region of the Moon, to the east-northeast of the walled plain Hipparchus. The outer wall is irregular and broken in several locations, forming the overall shape of a pentagon. The interior of Saunder has been flooded with lava, forming a...

 lie to the west and east, respectively. The crater Horrocks was named after the 17th-century English

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 astronomer Jeremiah Horrocks

Jeremiah Horrocks

Jeremiah Horrocks , sometimes given as Jeremiah Horrox , was an English astronomer who was the only person to predict, and one of only two people to observe and record, the transit of Venus of 1639.- Life and work :Horrocks was born in Lower Lodge, in...

.

The rim of Horrocks is somewhat irregular and polygon

Polygon

In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain orcircuit.A polygon is traditionally a plane figure that is bounded by a closed path, composed of a finite sequence of straight line segments...

al, particularly with an outward protrusion on the eastern rim. It has a small outer rampart. The inner wall is slumped, particularly along the northwest where it forms a heap of talus

Scree

Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...

. The interior floor is uneven, and it has a central mountain and hills. The crater is approximately 30 kilometers in diameter and 3 kilometers deep. It is from the Eratosthenian

Eratosthenian

The Eratosthenian period in the lunar geologic timescale runs from 3,200 million years ago to 1,100 million years ago. It is named after the crater Eratosthenes, whose formation marks the beginning of this period. The formation of the crater Copernicus marks its end, and the beginning of the...

period, which lasted from 3.2 to 1.1 billion years ago.

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 Horrocks.

Horrocks	Latitude	Longitude	Diameter
M	4.0° S	7.6° E	5 km
U	3.2° S	4.8° E	4 km