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

, crossing over to the

far side ''The Far Side'' is a single-panel comic created by Gary Larson and syndicated by Chronicle Features and then Universal Press Syndicate, which ran from December 31, 1979, to January 1, 1995 (when Larson retired as a cartoonist). Its surrealist ...

. It completely encircles the

Mare Orientale Mare Orientale (Latin ''orientāle'', the "eastern sea") is a lunar mare. It is located on the western border of the near side and far side of the Moon, and is difficult to see from an Earthbound perspective. Images from spacecraft have reveal ...

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

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. The center of the range is located at selenographic coor ...

, 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, having respective diameters of 620 km and 480 km. The material excavated to form Montes Rook came from a

mafic A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks in ...

layer below an anorthositic zone. Many of the peaks in this ring are composed of pure

anorthosite Anorthosite () is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most ...

. Sections of the gap between these sub-ranges contain long valleys filled in places with

basalt Basalt (; ) is an 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 surface of a rocky planet or moon. More than 90 ...

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 ...

, forming small

lunar maria 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' ...

. One such section along the northeastern part of the range has been named Lacus Veris. The selenographic

coordinate In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space. The order of the coordinates is sign ...

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

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

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

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...

, and not much detail can be seen. However a partial view of the range can be obtained by projecting an image of the range acquired from the Earth onto the surface of a white globe. This is how William K. Hartmann and

Gerard Kuiper Gerard Peter Kuiper (; ; born Gerrit Pieter Kuiper; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt. Kuiper is ...

discovered the ring shape of Montes Rook in the early 1960s.Hartmann, W. K. and G. P. Kuiper, 1962. Concentric Structures Surrounding Lunar basins. ''Comm. Lunar and Planetary Lab.'', 1, 51-66. Several named craters are embedded within the Montes Rook. Near the southwest outer edge are the craters

Nicholson Nicholson may refer to: People *Nicholson (name), a surname, and a list of people with the name Places Australia * Nicholson, Victoria * Nicholson, Queensland * Nicholson County, New South Wales * Nicholson River (disambiguation) * Nicholson ...

and Pettit. Kopff lies along the eastern inner edge, and Maunder on the northern inner side. Smaller craters include Lallemand to the northeast, Shuleykin to the south, and Fryxell in the west. Out of sight from the

, even during favorable

libration In lunar astronomy, libration is the wagging or wavering of the Moon perceived by Earth-bound observers and caused by changes in their perspective. It permits an observer to see slightly different hemispheres of the surface at different tim ...

s, are the craters Lowell to the northwest, and Golitsyn to the west-southwest.

References

{{reflist Rook, Montes