Montes Rook is a ring-shaped mountain range that lies along the western limb of the Moon

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...

, crossing over to the far side. It completely encircles the Mare Orientale

Mare Orientale

Mare Orientale is one of the most striking large scale lunar features, resembling a target ring bull's-eye. Located on the extreme western edge of the lunar nearside, this impact basin is difficult to see from an Earthbound perspective.Material from this basin was not sampled by the Apollo program...

, and forms part of a massive impact basin feature. This range in turn is encircled by the larger Montes Cordillera

Montes Cordillera

Montes Cordillera is a mountain range on the Moon. This feature forms the outer wall of peaks that surround the Mare Orientale impact basin, the inner ring being formed by the Montes Rook...

, which is separated from the Montes Rook by a rugged, ring-shaped plain.

The Montes Rook is actually a double-ring formation, sometimes divided into the outer Rook and the inner Rook. Sections of the gap between these sub-ranges contain long valleys filled in places with basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

ic 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...

, forming small lunar maria. One such section along the northeastern part of the range has been named Lacus Veris

Lacus Veris

Lacus Veris is a small lunar mare on the Moon. In selenographic coordinates, the mare centered at 16.5° S, 86.1° W and lies within a 396 km in diameter. The mare extends along an irregular 90° arc from east to north that is centered on the Mare Orientale, covering an area of about...

.

The selenographic coordinates of this range are 20.6° S, 82.5° W, and the diameter is 791 km. The range was named after the 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

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 Lawrence Rook. Due to its location this range is viewed from the edge from Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, and not much detail can be seen. However a partial view of the range can be obtained by projecting the surface of a globe. This rectified map was used to identify the Mare Orientale impact basin.

Several named craters are embedded within the Montes Rook. Near the southwest outer edge are the craters Nicholson

Nicholson (lunar crater)

Nicholson is a lunar impact crater located at the western limb. In this position it is subject to libration, which can limit observation. The crater is also viewed at a very oblique angle, so it is seen from the side when observed from the Earth. It is an irregular, somewhat pear-shaped formation...

 and Pettit

Pettit (lunar crater)

Pettit is a lunar impact crater that lies near the western limb of the Moon. In this location the crater is viewed nearly from the side by observers on Earth, and visibility can be significantly affected by libration effects....

. Kopff

Kopff (crater)

Kopff is a lunar crater that lies along the eastern edge of the inner Mare Orientale impact basin, on the western limb of the Moon. In this position the crater is seen from on edge from the Earth, and its visibility is affected by libration...

 lies along the eastern inner edge, and Maunder

Maunder (lunar crater)

Maunder is a lunar impact crater that is located on the far side of the Moon, just beyond the western limb. This region is sometimes brought into view during favorable librations, but not much detail can be seen. The crater lies at the northern end of the Mare Orientale, within the ring of...

 on the northern inner side. Smaller craters include Lallemand

Lallemand (crater)

Lallemand is a small lunar impact crater that lies near the western limb of the Moon, in a region where the visibility is affected by libration effects. Because of its location, when viewed from the Earth the crater is viewed nearly from the side, limiting the amount of detail that can be seen...

 to the northeast, Shuleykin

Shuleykin (crater)

Shuleykin is a small lunar impact crater that lies to the south of Mare Orientale, within the ring-shaped Montes Rook. It is located just on the far side of the Moon, but this area can be viewed from the Earth during periods of favorable libration and lighting, although it can only be seen from the...

 to the south, and Fryxell

Fryxell (crater)

Fryxell is a small lunar crater that lies amidst the western inner ring of the Montes Rook. This crater is located on the Moon's far side, at the extreme edge of the region of the surface sometimes brought into view of the Earth due to libration. Even under rare conditions of favorable lighting and...

 in the west. Out of sight from the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, even during favorable libration

Libration

In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...

s, are the craters Lowell

Lowell (lunar crater)

Lowell is a lunar impact crater that lies just beyond the western limb of the Moon. It is embedded within the northwestern part of the Montes Rook mountain ring of the Mare Orientale impact basin...

 to the northwest, and Golitsyn

Golitsyn (crater)

Golitsyn is a lunar impact crater that lies beyond the western limb on the far side of the Moon. It is located in the southwestern portion of the Montes Rook mountain range that forms one of the rings around the Mare Imbrium impact site...

to the west-southwest.