Exploring Shorty crater during the Apollo 17 mission to the Moon. This was the only Apollo mission to include a Geologist. NASA photo.

The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar science") is quite different from that of the Earth. The Moon lacks a significant atmosphere, which eliminates erosion due to weather, it does not possess any form of plate tectonics, it has a lower gravity, and because of its small size, it cooled more rapidly. The complex morphology of the lunar surface has been formed by a combination of processes, chief among which are impact cratering, and volcanism. The Moon is a differentiated body, which possesses a crust, mantle and core. Image File history File links Description: Image taken during the Apollo 17 mission to the Moon, in the Taurus-Littrow region. ... Image File history File links Description: Image taken during the Apollo 17 mission to the Moon, in the Taurus-Littrow region. ... Apollo 17 was the eleventh manned space mission in the NASA Apollo program and was the sixth and last manned mission to date to land on the Moon. ... A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology). ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Bulk silicate composition (estimated wt%) SiO2 44. ... Earth (IPA: , often referred to as the Earth, Terra, the World or Planet Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ... Weather is a term that encompasses phenomena in the atmosphere of a planet. ... Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ... Gravitation is a phenomenon through which all objects attract each other. ... Morphology is the following: In linguistics, morphology is the study of the structure of word forms. ... Tycho crater on Earths moon. ... This article is about volcanoes in geology. ... Earth cutaway from core to exosphere. ... Earth cutaway from core to exosphere. ... The planetary core consists of the innermost layers of a planet. ...

Geological studies of the Moon are based on a combination of Earth based telescope observations, measurements from orbiting spacecraft, lunar samples, and geophysical data. A few locations were sampled directly during the Apollo missions in the late 1960's and early 1970's, which returned approximately 385 kilograms of lunar rock and soil to Earth, as well as several missions of the Soviet Luna programme. The Moon is the only extraterrestrial body for which we possess samples with a known geologic context. A handful of lunar meteorites have been recognized on Earth, though their source craters on the Moon are unknown. A substantial portion of the lunar surface has not been explored and a number of geological questions remain unanswered. World geologic provinces Oceanic crust  0-20 Ma  20-65 Ma  >65 Ma Geologic provinces  Shield  Platform  Orogen  Basin  Large igneous province  Extended crust Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason))[1] is the science and study of the solid matter of a celestial body, its composition... 50 cm refracting telescope at Nice Observatory. ... Project Apollo was a series of human spaceflight missions undertaken by the United States of America (NASA) using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961–1975. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Soviet redirects here. ... The Luna programme (occasionally called Lunik) was a series of unmanned space missions sent to the Moon by the Soviet Union between 1959 and 1976. ... Lunar Meteorite Allan Hills 81005 A Lunar meteorite is a meteorite that is known to have originated on the Moon. ...

Formation

For a long time, the fundamental question regarding the history of the Moon was of its origin. Early hypotheses included fission from the Earth, capture, and co-accretion. Today, the giant impact hypothesis is widely accepted by the scientific community. Moon This work is copyrighted. ... In general fission is a splitting or breaking up of any substance into parts. ...

Fission hypothesis

The idea that the early Earth, with an accelerated rotation, expelled a piece of its mass was proposed by George Darwin (son of the famous biologist Charles Darwin). It was commonly assumed that the Pacific Ocean represented the scar of this event. However, today it is known that the oceanic crust that makes up this ocean basin is relatively young, about 200 million years old or less, whereas the Moon is much older. This hypothesis can not account for the angular momentum of the Earth-Moon system. George Howard Darwin Sir George Howard Darwin, F.R.S. (July 9, 1845 – December 7, 1912) was a British astronomer and mathematician, the second son and fifth child of Charles and Emma Darwin. ... Charles Robert Darwin FRS (12 February 1809 – 19 April 1882) was an English naturalist [1] who achieved lasting fame by producing considerable evidence that species originated through evolutionary change, at the same time proposing the scientific theory that natural selection is the mechanism by which such change occurs. ... Gyroscope. ...

Lunar capture

This hypothesis states that the Moon was captured, completely formed, by the gravitational field of the Earth. This is unlikely, since a close encounter with the Earth would have produced either a collision or an alteration of the trajectory of the body in question, so if it had indeed happened, the Moon probably would never return to meet again with the Earth. For this hypothesis to function, there would have to be a large atmosphere extended around the primitive Earth, which would be able to slow the movement of the Moon before it could escape. This hypothesis is considered to explain the irregular satellite orbits of Jupiter and Saturn; nevertheless, it is very difficult to believe that this would explain the origin of our moon. In addition, this hypothesis has difficulty explaining the similar oxygen isotope ratio of the two worlds. The gravitational field is a field (physics), generated by massive objects, that determines the magnitude and direction of gravitation experienced by other massive objects. ... Earth (IPA: , often referred to as the Earth, Terra, the World or Planet Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... View of Jupiters active atmosphere, including the Great Red Spot. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Isotopes are any of the several different forms of an element each having different atomic mass. ...

Co-accretion hypothesis

This hypothesis states that the Earth and the Moon formed together as a double system from the primoridial accretion disk of the Solar System. The problem with this hypothesis is that it does not explain the angular momentum of the Earth-Moon system, nor why the Moon is depleted in metallic iron.

Giant impact theory

Main article: Giant impact theory

At present the best explanation for the origin of the Moon involves a collision of two protoplanetary bodies during the early accretional period of Solar system evolution. This "giant impact theory", which became popular in 1984 (although it originated in the mid-1970s) satisfies the orbital conditions of the Earth and Moon and can account for the relatively small metallic core of the Moon. Collisions between planetesimals are now recognized to lead to the growth of planetary bodies early in the evolution of the solar system, and in this framework it is inevitable that large impacts will sometimes occur when the planets are nearly formed. The Big Splash The giant impact theory (or Big Splash or Big Whack; cf. ... Major features of the Solar System (not to scale): The Sun, the eight planets, the asteroid belt containing the dwarf planet Ceres, outermost there is the dwarf planet Pluto (the dwarf planet Eris not shown), and a comet. ... In cosmogony, planetesimals are objects thought to exist within solar nebulae. ...

The theory requires a collision between a body about 90% the present size of the Earth, and another the diameter of Mars (half of the terrestrial radius and a tenth of its mass). The colliding body has sometimes been referred to as Theia, the mother of Selene, the Moon goddess in greek mythology. This size ratio is needed in order for the resulting system to possess sufficient angular momentum to match the current orbital configuration. Such an impact would have put enough material into orbit about the Earth to have eventually accumated to formed the Moon. Note: This article contains special characters. ... Theia (THAY-uh) is the hypothetical planet that, according to the giant impact theory of the Moons formation, collided with Earth over four billion years ago. ... Roman sculpture of the torch-bearing moon goddess Luna, or Diana Lucifera (Diana Bringer of Light), who was equated with the Greek Selene (Vatican Museums) In Greek mythology, Selene (Σελήνη, moon; Modern Greek pronunciation IPA: ) was an archaic lunar deity and the daughter of the titans Hyperion and Theia. ... Statue of Ceres, the Roman goddess of the agriculture A goddess is a female deity, in contrast with a male deity known as a god. Many cultures have goddesses, sometimes alone, but more often as part of a larger pantheon that includes both the conventional genders and in some cases... // The word mythology (Greek: μυθολογία, from μυθος mythos, a story or legend, and λογος logos, an account or speech) literally means the (oral) retelling of myths – stories that a particular culture believes to be true and that use supernatural events or characters to explain the nature of the universe and humanity. ...

Computer simulations of this event appear to show that the collision must occur with a somewhat glancing blow. This will cause a small portion of the colliding body to form a long arm of material that will then shear off. The asymmetrical shape of the Earth following the collision then causes this material to settle into an orbit around the main mass. The energy involved in this collision is impressive: trillions of tons of material would have been vaporized and melted. In parts of the Earth the temperature would have risen to 10,000 °C. A computer simulation or a computer model is a computer program that attempts to simulate an abstract model of a particular system. ... Fig. ... The degree Celsius (symbol: °C) is an SI derived unit of temperature. ...

This formation theory helps explain why the Moon possesses only a small iron core (roughly 25% of its radius, in comparison to about 50% for the Earth). Most of the iron core from the impacting body is predicted to have accreted to the core of the Earth. The lack of volatiles in the lunar samples is also in part explained by the energy of the collision. The energy liberated during the reaccreation of material in orbit about the Earth would have been sufficient to melt a large portion of Moon, leading to the generation of a magma ocean. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Magma is molten rock located beneath the surface of the Earth (or any other rocky planet), and which often collects in a magma chamber. ...

The newly formed moon orbited at about one-tenth the distance that it does today, and became tidally-locked with the Earth, where one side continually faces toward the Earth. The geology of the Moon has since been independent of the Earth. While this theory explains many aspects of the Earth-Moon system, there are still a few unresolved problems facing this theory, such as the Moon's volatile elements not being as depleted as expected from such an energetic impact^[1]. Tidal locking makes one side of an astronomical body always face another, like the Moon facing the Earth. ... Look up element in Wiktionary, the free dictionary. ...

Geologic history

The geological history of the Moon has been defined into six major epochs, called the lunar geologic timescale. Starting about 4.5 billion years ago, the newly formed Moon was in a molten state and was orbiting much closer to the Earth. The resulting tidal forces deformed the molten body into an ellipsoid, with the major axis pointed towards Earth. The lunar geologic timescale (or perhaps more properly the selenologic timescale) divides the history of Earths Moon into six generally recognized geologic periods: Copernician Period : 1100 MY to present Eratosthenian Period : 3200 MY to 1100 MY Upper Imbrian Epoch : 3800 MY to 3200 MY Lower Imbrian Epoch : 3850 MY... Physics In physics, melting is the process of heating a solid substance to a point (called melting point) where it turns liquid. ... Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ... 3D rendering of an ellipsoid In mathematics, an ellipsoid is a type of quadric that is a higher dimensional analogue of an ellipse. ...

The first important event in the geologic evolution of the Moon was the crystallization of near global magma ocean. It is not known with certainty what its depth was, but several studies imply a depth of about 500 km, or greater. The first minerals to form in this ocean were the iron and magnesium silicates olivine and pyroxene. Because these minerals were denser than the molten material around them, they sank. After crystallization was about 75% complete, less dense anorthositic plagioclase feldspar crystallized and floated, forming an anorthositic crust about 50 km in thickness. The majority of the magma ocean crystallized quickly (within about 100 million years or less), though the final remaining KREEP-rich magmas, which are highly enriched in incompatible and heat producing elements, could have remained partially molten for several hundred (and perhaps 1 billion) years. It appears that the final KREEP-rich magmas of the magma ocean eventually became concentrated within the region of Oceanus Procellarum and the Imbrium basin, a unique geologic province that is now known as the Procellarum KREEP Terrane. Crystal (disambiguation) Insulin crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ... Olivine basalt The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... Anorthosite is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar (90-100%), and a minimal mafic component (0-10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... KREEP stands for potassium (atomic symbol K), rare earth elements (REE), and phosphorus (P). ... The Ocean of Storms of the Moon. ... Oblique view of Mare Imbrium looking south towards Copernicus crater. ... This article, which relates to the Moon, is a stub. ...

Quickly after the lunar crust formed, or even as it was forming, different types of magmas that would give rise to the Mg-suite norites and troctolites^[2] began to form, although the exact depths at which this occurred are not known precisely. Recent theories suggest that Mg-suite plutonism was largely confined to the region of the Procellarum KREEP Terrane, and that these magmas are genetically related to KREEP in some manner, though their origin is still highly debated in the scientific community. The oldest of the Mg-suite rocks have crystallization ages of about 3.85 Ga. However, it should be noted that the last large impact that could have excavated deep into the crust (the Imbrium basin) also occurred at 3.85 Ga. Thus, it seems probable that Mg-suite plutonic activity continued for a much longer time, and that younger plutonic rocks exist deep below the surface. General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... In geology, the term suite can refer to a collection of rock specimens from a given area, or it can refer to the succession of closely associated sedimentary strata or layers, especially a repeated sequence of layers. ... Norite is a mafic intrusive igneous rock composed largely of the calcium rich plagioclase labradorite and hypersthene with olivine. ... Troctolite is a rare ultramafic intrusive rock type. ... Plutonism was a theory of Geology around the turn of the 19th Century that claimed that volcanic activity was the source of rocks on the surface of the Earth. ... This article, which relates to the Moon, is a stub. ... Giga-annum, usually abbreviated as Ga, is a unit of time equal to 10^9 years. ... Oblique view of Mare Imbrium looking south towards Copernicus crater. ...

Analysis of the lunar samples seem to imply that a significant percentage of the lunar impact basins formed within a very short period of time between about 4 and 3.85 Ga. This hypothesis is referred to as the lunar cataclysm or late heavy bombardment. However, it is now recognized that ejecta from the Imbrium impact basin (one of the youngest large impact basins on the Moon) should be found at all of the Apollo landing sites. It is thus possible that ages for some impact basins (in particular Mare Nectaris) could have been mistakenly assigned the same age as Imbrium. The Late Heavy Bombardment (LHB) was a period approximately 3. ... The Sea of Nectar (Mare Nectaris) is a small lunar mare or sea (a volcanic lava plain noticeably darker than the rest of the moons surface) located between the Sea of Tranquillity (Mare Tranquillatis) and the Sea of Fecundity (Mare Fecunditatis). ...

The lunar mare represent ancient flood basaltic eruptions. In comparison to terrestrial lavas, these contain higher iron abundances, have low viscosities, and some contain highly elevated abundances of the titanium-rich mineral ilmenite. The majority of basaltic eruptions occurred between about 3 and 3.5 Ga, though some mare samples have ages as old as 4.2 Ga, and the youngest (based on the method of crater counting) are believed to have erupted only 1 billion years ago. Along with mare volcanism came pyroclastic eruptions, which launched molten basaltic materials hundreds of kilometers away from the volcano. A large portion of the mare formed, or flowed into, the low elevations associated with the nearside impact basins. However, it must be noted that Oceanus Procellarum does not correspond to any known impact structure, and the lowest elevations of the Moon within the farside South Pole-Aitken basin are only modesty covered by mare (see lunar mare for a more detailed discussion). A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... Pyroclastic rocks are formed from lavas which are ejected into the air, as occur in pyroclastic flows or Plinian eruptions. ... Volcano 1. ... The Ocean of Storms of the Moon. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ...

Impacts by meteorites and comets are the only substantial geologic force acting on the Moon today. Some of the most important craters used in lunar stratigraphy formed in this recent epoch. For example, the Copernicus crater, which has a depth of 3.76 km and a radius of 93 km, is believed to have formed about 900 million years ago (though this is debatable). The Apollo 17 mission landed in an area in which the material coming from the Tycho crater might have been sampled. The study of these rocks seem to indicate that this crater could have formed 100 million years ago, though this is debatable as well. The surface has also experienced space weathering due to high energy particles, solar wind implantation, and micrometeorite impacts. This process causes the ray systems associated with young craters to darken until it matches the albedo of the surrounding surface. However, if the composition of the ray is different than the underlying crustal materials (as might occur when a "highland" ray is emplaced on the mare), the ray could be visible for much longer times. Worlds second largest Meteorite in Culiacan, Mexico A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small astronomical object similar to an asteroid but composed largely of ice. ... Tycho crater on Earths moon. ... Copernicus is a prominent lunar impact crater located on the eastern Oceanus Procellarum. ... Apollo 17 was the eleventh manned space mission in the NASA Apollo program and was the sixth and last manned mission to date to land on the Moon. ... Tycho is a prominent lunar impact crater located in the southern lunar highlands. ... The plasma in the solar wind meeting the heliopause For the British comic, see Solar Wind (comic). ... A Micrometeoroid (also micrometeorite, micrometeor) is a tiny meteoroid; a small particle of rock from space, usually weighing less than a gram, that poses a threat to space exploration. ... Crater ray system on the far side of the Moon. ...

Lunar landscape

The lunar landscape is characterized by impact craters, their ejecta, a few volcanoes, hills, lava flows and depressions filled by magma. Tycho crater on Earths moon. ... Volcano 1. ... In computer programming jargon, lava flow is a problem in which computer code, usually written under less than optimal conditions, is put into production and then built on when still in a developmental state. ...

Lunar highlands and maria

The most distinctive aspect of the Moon is the contrast between its light and dark zones. Lighter surfaces are the lunar highlands, which receive the name of terrae (singular terra, from the Latin for Earth), and the darker plains are called maria (singular mare, from the Latin for sea), after Johannes Kepler who introduced the name in the 1600's. The highlands are anorthositic in composition, whereas the maria are basaltic. The maria often coincide with the "lowlands," but it is important to note that the lowlands (such as within the South Pole-Aitken basin) are not always covered by maria. The highlands are older than the visible maria, and hence are more heavily cratered. Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Earth (IPA: , often referred to as the Earth, Terra, the World or Planet Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... Sea as seen from jetty in Frankston, Australia Look up Sea in Wiktionary, the free dictionary. ... Johannes Kepler (December 27, 1571 – November 15, 1630), a key figure in the scientific revolution, was a German mathematician, astronomer, astrologer, and an early writer of science fiction stories. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ...

Impact cratering

Mare Imbrium and the Copernicus crater. NASA photo.

It may be surprising to learn that the origin of the Moon's craters as impact features became widely accepted only in the 1940s. This realization allowed the impact history of the Moon to be gradually worked out by means of the geologic principle of superposition. That is, if a crater (or its ejecta) overlaid another, it must be the younger. The amount of erosion experienced by a crater was another clue to its age, though this is more subjective. Adopting this approach in the late 1950s, Gene Shoemaker took the systematic study of the Moon away from the astronomers and placed it firmly in the hands of the lunar geologists. Mare Imbrium Apollo 17 (NASA, PD) Mare Imbrium and Copernicus crater http://nssdc. ... Mare Imbrium Apollo 17 (NASA, PD) Mare Imbrium and Copernicus crater http://nssdc. ... Oblique view of Mare Imbrium looking south towards Copernicus crater. ... Copernicus is a prominent lunar impact crater located on the eastern Oceanus Procellarum. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... The 1940s decade ran from 1940 to 1949. ... The law of superposition is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields dealing with geological stratigraphy. ... The 1950s was the decade spanning from the 1st of January, 1950 to the 31st December, 1959. ... Eugene Shoemaker at a stereoscopic microscope used for asteroid discovery Eugene Merle Shoemaker (or Gene Shoemaker) (April 28, 1928 â€“ July 18, 1997) was one of the founders of the fields of planetary science and is best known for co-discovering the Comet Shoemaker-Levy 9 with his wife Carolyn Shoemaker...

Impact cratering is the most notable geological process on the Moon. The craters are formed when a solid body, such as an asteroid or comet, collides with the surface at a high velocity (mean impact velocities for the Moon are about 17 km per second). The kinetic energy of the impact creates a compression shock wave that radiates away from the point of entry. This is succeeded by a rarefaction wave, which is responsible for propelling most of the ejecta out of the crater. Finally there is a hydrodynamic rebound of the floor that can create a central peak. Tycho crater on Earths moon. ... 253 Mathilde, a C-type asteroid. ... A comet is a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail â€” both primarily from the effects of solar radiation upon the comets nucleus, which itself is a minor body composed of rock, dust... Rarefaction is the reduction of a mediums density, or the opposite of compression. ...

These craters appear in a continuum of diameters across the surface of the Moon, ranging in size from tiny pits to the immense South Pole-Aitken Basin with a diameter of nearly 2,500 km and a depth of 13 km. In a very general sense, the lunar history of impact cratering follows a trend of decreasing crater size with time. In particular, the largest impact basins were formed during the early periods, and these were successively overlaid by smaller craters. The size frequency distribution (SFD) of crater diameters on a given surface (that is, the number of craters as a function of diameter) approximately follows a power law with increasing number of craters with decreasing crater size. The vertical position of this curve can be used to estimate the age of the surface. The South Pole-Aitken basin is an impact crater on Earths Moon. ... See Also: Watt In physics, a power law relationship between two scalar quantities x and y is any such that the relationship can be written as where a (the constant of proportionality) and k (the exponent of the power law) are constants. ...

King crater displays the characteristic features of a large impact formation, with a raised rim, slumped edges, terraced inner walls, a relatively flat floor with some hills, and a central ridge. The Y-shaped central ridge is unusually complex in form. NASA photo.

The most recent impacts are distinguished by well-defined features, including a sharp-edged rim. Small craters tend to form a bowl shape, while larger impacts can have a central peak with flat floors. Larger craters generall display slumping features along the inner walls that can form terraces and ledges. The largest impact basins, the multiring basins, can even have secondary concentric rings of raised material. Image File history File links Download high resolution version (673x637, 400 KB) Description: This picture of King crater on the far side of the Moon was taken during the Apollo 16 mission. ... Image File history File links Download high resolution version (673x637, 400 KB) Description: This picture of King crater on the far side of the Moon was taken during the Apollo 16 mission. ... King is a prominent lunar impact crater that is located on the far side of the Moon, and can not be viewed directly from Earth. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ...

The impact process excavates high albedo materials that initially gives the crater, ejecta, and ray system a bright appearance. The process of space weathering gradually decreases the albedo of this material such that the rays fade with time. Gradually the crater and its ejecta undergo impact erosion from micrometeorites and smaller impacts. This erosioanl process softens and rounds the features of the crater. The crater can also be covered in ejecta from other impacts, which can submerge features and even bury the central peak. Albedo is a ratio of scattered to incident electromagnetic radiation power. ... Crater ray system on the far side of the Moon. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ...

The ejecta from large impacts can include larges blocks of material that reimpact the surface to form secondary impact craters. These craters are sometimes formed in clearly discernable radial patterns, and generally have shallower depths than primary craters of the same size. In some cases an entire line of these blocks can impact to form a valley. These are distinguished from catena, or crater chains, which are linear strings of craters that are formed when the impact body breaks up prior to impact.

Generally speaking a lunar crater is roughly circular in form. It has been demonstrated in laboratory experiments that even low-angle impacts tend to produce circular craters, and there are few lunar craters that have formed naturally elliptical outlines. However, a low angle impact can produce a central peak that is offset from the mid-point of the crater. In addition, such an impact will produce an asymmetrical ejecta and ray system.

Dark-halo craters are formed when an impact excavates lower albedo material from beneath the surface, then deposits this darker ejecta around the main crater. This can occur when an area of darker basaltic material, such as that found on the lunar mare, is later covered by lighter ejecta derived from more distant impacts in the highlands. This covering conceals the darker material below, which is later excavated by subsequent craters. Albedo is a ratio of scattered to incident electromagnetic radiation power. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ...

The largest impacts produced melt sheets of molten rock that covered portions of the surface which could be as thick as a kilometer. Examples of such impact melt can be seen in the northeastern part of the Mare Orientale impact basin. 1967 photograph made by NASAs Lunar Orbiter 4 Like a target ring bulls-eye, the lunar mare Mare Orientale (the eastern sea) is one of the most striking large scale lunar features. ...

Tycho crater, with rays extending from its rim

Download high resolution version (2048x1360, 1573 KB)Tycho crater on the Moon. ... Download high resolution version (2048x1360, 1573 KB)Tycho crater on the Moon. ... Tycho is a prominent lunar impact crater located in the southern lunar highlands. ...

Volcanism and the maria

Main article: Lunar mare

The major products of volcanic processes on the Moon are evident to the Earth-bound observer in the form of the lunar maria. These are large flows of basaltic lava that correspond to low-albedo surfaces covering nearly a third of the near side. Only a few percent of the farside has been affected by mare volcanism. Even before the Apollo missions confirmed it, most scientists believed that the maria were lava-filled plains, since they possessed lava flow patterns and collapses attributed to lava tubes. A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... This article is about volcanoes in geology. ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... Albedo is a ratio of scattered to incident electromagnetic radiation power. ... Lycian Apollo, early Imperial Roman copy of a fourth century Greek original (Louvre Museum) In Greek and Roman mythology, Apollo (Ancient Greek , Apóllōn; or Ἀπέλλων, Apellōn), the ideal of the kouros, was the archer-god of medicine and healing and also a bringer of death-dealing plague; as... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... In computer programming jargon, lava flow is a problem in which computer code, usually written under less than optimal conditions, is put into production and then built on when still in a developmental state. ... Thurston Lava Tube in Hawaii Volcanoes National Park. ...

The ages of the mare basalts have been determined both by direct radiometric dating and by the technique of crater counting. The oldest radiometric ages are about 4.2 Ga, whereas the youngest ages determined from crater counting are about 1 Ga (1 Ga = 1 billion years old). Volumetrically, most of the mare formed between about 3 and 3.5 Ga. The youngest lavas erupted within Oceanus Procellarum, whereas some of the oldest appear to be located on the farside. The maria are clearly younger than the surrounding highlands given their lower density of impact craters. Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ... This article, which relates to the Moon, is a stub. ... The Ocean of Storms of the Moon. ...

A large portion of maria erupted within, or flowed into, the low lying impact basins on the lunar nearside. Nevertheless, it is unlikely that a causal relationship exists between the impact event and mare volcanism because the impact basins are much older (by about 500 million years) than the mare fill. Furthermore, Oceanus Procellarum, which is the largest expanse of mare volcanism on the Moon, does not correspond to any known impact basin. It is commonly suggested that the reason the mare only erupted on the nearside is that the nearside crust is thinner than the farside. While crustal thickness variations might act to modulate the amount of magma that ultimately reaches the surface, this hypothesis does not explain why the farside South Pole-Aitken basin, whose crust is thinner than Oceanus Procellarum, was only modestly filled by volcanic products. Finally, it should be noted that the Earth's gravity played no preferential role in causing mare volcanism to occur on the near side, as the Earth's gravitational attraction is exactly balanced by the centrifugal acceleration resulting from the Moon's rotation. The Ocean of Storms of the Moon. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ...

Another type of deposit associated with the mare, although it also covers the highland areas, are the "dark mantle" deposits. These deposits cannot be seen with the naked eye, but they can be seen in images taken from telescopes or orbiting spacecraft. Before the Apollo missions, scientists believed that they were deposits produced by pyroclastic eruptions. Some deposits appear to be associated with dark elongated ash cones, reinforcing the idea of pyroclasts. The existence of pyroclastic eruptions was later confirmed by the discovery of glass spherules similar to those found in pyroclastic eruptions here on Earth. Lycian Apollo, early Imperial Roman copy of a fourth century Greek original (Louvre Museum) In Greek and Roman mythology, Apollo (Ancient Greek , Apóllōn; or Ἀπέλλων, Apellōn), the ideal of the kouros, was the archer-god of medicine and healing and also a bringer of death-dealing plague; as... Pyroclastic rocks are formed from lavas which are ejected into the air, as occur in pyroclastic flows or Plinian eruptions. ... Puʻu ʻŌʻō, a cinder-and-spatter cone on Kīlauea, Hawaiʻi Volcanic cones are among the simplest volcano formations. ...

Many of the lunar basalts contain small holes called vesicles, which were formed by gas bubbles exsolving from the magma at the vacuum conditions encountered at the surface. It is not known with certainty which gases escaped these rocks, but carbon monoxide is one candidate. In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ... Carbon monoxide, with the chemical formula CO, is a colourless, odourless and tasteless gas. ...

The samples of pyroclastic glasses are of green, yellow, and red tints. The difference in color indicates the concentration of titanium that the rock possesses, with the green particles having the lowest concentrations (about 1%), and red particles having the highest concentrations (up to 14%, much more than the basalts with the highest concentrations). Pyroclastic rocks are formed from lavas which are ejected into the air, as occur in pyroclastic flows or Plinian eruptions. ...

Rilles

Volcanic rilles near the crater Prinz.

Basaltic eruptions on the Moon sometimes resulted in the formation of localized lava channels. Rilles generally fall into three categories, consisting of sinuous, arcuate, or linear shapes. By following these meandering rilles back to their source, they often lead to an old volcanic vent. One of the most notable sinuous rilles is the Vallis Schröteri feature, located in the Aristarchus plateau along the eastern edge of Oceanus Procellarum. Image File history File links Download high-resolution version (1215x1185, 367 KB) Description: This picture of the flooded Prinz crater was taken from the Apollo 15. ... Image File history File links Download high-resolution version (1215x1185, 367 KB) Description: This picture of the flooded Prinz crater was taken from the Apollo 15. ... A rille is grasso is an idiot to describe any of the long, narrow depressions in the lunar surface that resemble channels. ... Vallis Schröteri is a sinuous valley on the surface of the Moon. ... The Ocean of Storms of the Moon. ...

Lunar domes

Volcanic domes within the Rümker Mons complex.

A variety of shield volcanos can be found in selected locations on the lunar surface, such as on Mons Rümker. These are believed to be formed by relatively viscous, possibly silica-rich lava, erupting from localized vents. The resulting lunar domes are wide, rounded, circular features with a gentle slope rising in elevation a few hundred meters to the mid-point. They are typically 8-12 km in diameter, but can be up to 20 km across. Some of the domes contain a small pit at their peak. Image File history File links Download high-resolution version (2373x2406, 987 KB) Description: This picture of the Mons Rümker rise on the Oceanus Procellarum was taken from the Apollo 15 while in lunar orbit. ... Image File history File links Download high-resolution version (2373x2406, 987 KB) Description: This picture of the Mons Rümker rise on the Oceanus Procellarum was taken from the Apollo 15 while in lunar orbit. ... Shield volcano Mauna Kea, a shield volcano, on the Island of Hawai‘i with a light dusting of snow. ... Mons Rümker is an isolated volcanic formation that is located in the northwest part of the Moons near side, at selenographic coordinates 40. ... Lunar domes on Mons Rümker. ...

Wrinkle-ridges

Wrinkle ridges within the Letronne crater.

Wrinkle ridges are features created by compressive tectonic forces within the mare. These features represent buckling of the surface and form long ridges across parts of the mare. Some of these ridges may outline buried craters or other features beneath the mares. A prime example of such an outlined feature is the Letronne crater. Image File history File links AS16-M-2995. ... Image File history File links AS16-M-2995. ... A wrinkle-ridge is a type of feature commonly found on Lunar mares. ... Letronne is the lava-flooded remnant of a lunar crater. ...

Graben

Rima Ariadaeus is a graben. NASA photo taken during Apollo 10 mission.

Graben are tectonic features that form under extension stresses. Structurally, they are composed of two normal faults, with a down-dropped block between them. Most graben are found within the lunar mare near the edges of large impact basins. Image File history File links Download high resolution version (640x643, 350 KB) Description: This is an image of Rima Ariadaeus, a linear rille on the lunar surface that extends for over 300 km. ... Image File history File links Download high resolution version (640x643, 350 KB) Description: This is an image of Rima Ariadaeus, a linear rille on the lunar surface that extends for over 300 km. ... USGS image A graben is a depressed block of land bordered by parallel faults. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Apollo 10 was the fourth manned mission in the Apollo program, and the first (and only manned Saturn V) mission to launch from pad 39B. The mission included the second crew to orbit the Moon, and the test of the lunar module in lunar orbit. ...

Regolith

The surface of the Moon has been subject to billions of years of collisions with both small and large asteroidal and cometary materials. Over time, these impact processes have pulverized and "gardened" the surface materials, forming a fine grained layer termed "regolith". The thickness of the regolith varies between 2 meters beneath the younger maria, to up to 20 meters beneath the oldest surfaces of the lunar highlands. The regolith is predominantly composed of materials found in the region, but also contains traces of materials ejected by distant impact craters. The term "meta-regolith" is often used to describe the heavily fractured bedrock directly beneath the near-surface regolith layer.

The regolith contains rocks, fragments of minerals from the original bedrock, and glassy particles formed during the impacts. In most of the lunar regolith, half of the particles are made of mineral fragments fused by the glassy particles; these objects are called agglutinates. The chemical composition of the regolith varies according to its location; the regolith in the highlands is rich in aluminium, just as the rocks in those regions. The regolith in the maria is rich in iron and magnesium, as the basaltic rocks from which it is made of. Volcanic bombs are globules of molten rock (tephra) larger than 2. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ...

The lunar regolith is very important because it also stores information about the history of the Sun. The atoms that compose the solar wind – mostly helium, neon, carbon and nitrogen – hit the lunar surface and insert themselves into the mineral grains. Upon analyzing the composition of the regolith, particularly its isotopic composition, it is possible to determine if the activity of the Sun has changed with time. The gases of the solar wind could be useful for future lunar bases, since oxygen, hydrogen (water), carbon and nitrogen are not only essential to sustain life, but are also very useful in the production of fuel. The Sun is the star of our solar system. ... The plasma in the solar wind meeting the heliopause For the British comic, see Solar Wind (comic). ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... General Name, Symbol, Number neon, Ne, 10 Chemical series noble gases Group, Period, Block 18, 2, p Appearance colorless Atomic mass 20. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... Isotopes are any of the several different forms of an element each having different atomic mass. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... Fuel is any material that is capable of releasing energy when its chemical or physical structure is changed or converted. ...

The lunar magma ocean

The first rocks brought back by Apollo 11 were basalts. In spite that the mission landed on Mare Tranquillitatis), a few millimetric fragments of rocks coming from the highlands were picked up. These are composed mainly of plagioclase feldspar; some fragments were composed exclusively of anorthositic plagioclase. The identification of these mineral fragments led to the bold hypothesis that a large portion of the Moon was once molten, and that the crust formed by fractional crystallization of this magma ocean. Apollo 11 was the first manned mission to land on the Moon. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... The Sea of Tranquility of the Moon. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ...

A natural outcome of the giant impact event is that the materials that reaccreted to form the Moon must have been hot. Current models predict that a large portion of the Moon would have been molten shortly after the Moon formed, with estimates for the depth of this magma ocean ranging from about 500 km to full moon melting. Crystallization of this magma ocean would have given rise to a differentiated body with a compositionally distict crust and mantle and accounts for the major suites of lunar rocks.

As crystallization of the lunar magma ocean proceded, minerals such as olivine and pyroxene would have precipitated and sank to form the lunar mantle. After crystallization was about three-quarters complete, anorthositic plagioclase would have begun to crystallize, and because of its low density, float, forming an anorthositic crust. Importantly, elements that are incompatible (i.e., those that partion preferentially into the liquid phase) would have been progressively concentrated into the magma as crystallization progressed, forming an KREEP-rich magma that initially should have been sandwhiched between the crust and mantle. Evidence for this scenario comes from the highly anorthositc composition of the lunar highland crust, as well as the existence of KREEP-rich materials. KREEP stands for potassium (atomic symbol K), rare earth elements (REE), and phosphorus (P). ...

Image File history File links Moonhighlandsformation_lmb. ...

Lunar rocks

Surface materials

The Apollo program brought back 381.7 kg (841.5 lb) of lunar surface material, most of which is stored at the Lunar Receiving Laboratory in Houston, Texas. These rocks have proved to be invaluable in deciphering the geologic evolution of the Moon. Lunar rocks are in large part made of the same common rock forming minerals as found on Earth, such as Olivine, Pyroxene, and Plagioclase Feldspar (Anorthosite). The mineral ilmenite is highly abundant in some mare basalts, and a new mineral named Armalcolite (named for Armstrong, Aldrin, and Collins, the three members of the Apollo 11 crew) was first discovered in the lunar samples. Description Role: Earth and Lunar Orbit Crew: 3; CDR, CM pilot, LM pilot Dimensions Height: 36. ... Genesis Rock returned by the Apollo 15 mission. ... First samples from the Moon being delivered to LRL in 1969 The Lunar Receiving Laboratory (LRL) is a facility at NASAs Lyndon B. Johnson Space Center (Building 37) that was constructed to quarantine astronauts and material brought back from the Moon during the Apollo program. ... Nickname: Bayou City Location in the state of Texas Coordinates: Counties Harris County Fort Bend County Montgomery County Mayor Bill White Area    - City 1,558 km²  (601. ... Olivine basalt The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ... Armalcolite is a mineral that was discovered at Tranquility Base on the Moon by the Apollo 11 crew in 1970. ... Apollo 11 was the first manned mission to land on the Moon. ...

The maria are composed predominantly of basalt, whereas the highland regions are iron-poor and composed primarily of anorthosite, a plagioclase feldspar that is rich in aluminum and calcium. Another significant component of the crust are the igneous Mg-suite rocks, such as the troctolites, norites, and KREEP-basalts. These rocks are believed to be genetically related to the petrogenesis of KREEP. Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... Anorthosite is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar (90-100%), and a minimal mafic component (0-10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... Troctolite is a rare ultramafic intrusive rock type. ... Norite is a mafic intrusive igneous rock composed largely of the calcium rich plagioclase labradorite and hypersthene with olivine. ... KREEP stands for potassium (atomic symbol K), rare earth elements (REE), and phosphorus (P). ...

Composite rocks on the lunar surface often appear in the form of breccias. Of these, the subcategories are called fragmental, granulitic, and impact-melt breccias, depending on how they were formed. The mafic impact melt breccias, which are typified by the low-K Fra Mauro composition, have a higher proportion of iron and magnesium than typical upper crust anorthositic rocks, as well as higher abundances of KREEP. In geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements. ... Breccia, derived from the Latin word for broken, is a sedimentary rock composed of angular fragments in a matrix that may be of a similar or a different material. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ...

Composition of the maria

The main characteristics of the basaltic rocks with respect to the rocks of the lunar highlands is that the basalts contain higher abundances of olivine and pyroxene, and less plagioclase. They are more rich in iron than terrestrial basalts, and also have lower viscosities. Some of them have high abundances of a ferro-titanic oxide called ilmenite. Since the first sampling of rocks contained a high content of ilmenite and other related minerals, they received the name of "high titanium" basalts. The Apollo 12 mission returned to Earth with basalts of lower titanium concentrations, and these were dubbed "low titanium" basalts. Subsequent missions, including the Soviet unmanned probes, returned with basalts with even lower concentrations, now called "very low titanium" basalts. The Clementine space probe returned data showing that the mare basalts possess a continuum in titanium concentrations, with the highest concentration rocks being the least abundant. Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... Olivine basalt The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... An oxide is a chemical compound of oxygen with other chemical elements. ... Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ... Apollo 12 was the sixth manned mission in the Apollo program and the second to land on the Moon. ... Motto: Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) (Russian: Workers of the world, unite!) Anthem: The Internationale (1922-1944) Hymn of the Soviet Union (1944-1991) Capital (and largest city) Moscow None; Russian de facto Government Federation of Soviet Republics  - Last President Mikhail Gorbachev  - Last Premier Ivan Silayev Establishment October Revolution   - Declared... Clementine was a joint space project between the Ballistic Missile Defense Organization (BMDO, previously the Strategic Defense Initiative Organization, or SDIO) and NASA. The objective of the mission was to test sensors and spacecraft components under extended exposure to the space environment and to make scientific observations of the Moon...

Study of lunar rocks

Most of the rocks brought from the Moon are stored in the Lunar Curatorial Facility in the Johnson Space Center in Houston, Texas. A small percentage is distributed in auxiliary installations at Brooks Air Force Base, near San Antonio, Texas. Many lunar samples are found in laboratories of researchers worldwide. A small number of these rocks is available for public display in museums, and only three pieces can be touched by the public. These are the "touchable rocks", cut from basaltic rocks obtained by Apollo 17. One of these rocks is located at the Smithsonian Institution's National Air and Space Museum in Washington, D.C. Another piece is located in the Houston Space Center, located near the Johnson Space Center. The third rock can be found inside the Museum of the Sciences in the National Autonomous University of Mexico. First samples from the Moon being delivered to LRL in 1969 The Lunar Receiving Laboratory (LRL) is a facility at NASAs Lyndon B. Johnson Space Center (Building 37) that was constructed to quarantine astronauts and material brought back from the Moon during the Apollo program. ... An aerial view of the complete Johnson Space Center facility in Houston, Texas in 1989. ... Houston redirects here. ... Official language(s) See: Languages of Texas Capital Austin Largest city Houston Area  Ranked 2nd  - Total 268,581 sq mi (695,622 km²)  - Width 773 miles (1,244 km)  - Length 790 miles (1,270 km)  - % water 2. ... Brooks Air Force Base was a United States Air Force base located in San Antonio, Texas. ... Nickname: Alamo City; River City Location in the state of Texas Coordinates: Counties Bexar County Mayor Phil Hardberger Area    - City 1067. ... Apollo 17 was the eleventh manned space mission in the NASA Apollo program and was the sixth and last manned mission to date to land on the Moon. ... The Smithsonian Institution Building or Castle on the National Mall serves as the Institutions headquarters. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Nickname: DC, The District Motto: Justitia Omnibus (Justice for All) Location of Washington, D.C., in relation to the states Maryland and Virginia. ... The library of the National Autonomous University of Mexico. ...

Mineral composition of lunar rocks

Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... Olivine basalt The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ... Anorthosite is a phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar (90-100%), and a minimal mafic component (0-10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. ... Norite is a mafic intrusive igneous rock composed largely of the calcium rich plagioclase labradorite and hypersthene with olivine. ... Troctolite is a rare ultramafic intrusive rock type. ... Basalt Columnar basalt at Sheepeater Cliff in Yellowstone Basalt (IPA: ) is a common gray to black volcanic rock. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ...

Common lunar minerals

Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Olivine basalt The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Ilmenite (FeTiO3) is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and plutonic igneous rocks. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...

Interior structure of the Moon

The current model of the interior of the Moon was derived using seismometers left behind during the manned Apollo program missions, as well as investigations of the Moon's gravity field and rotation. Seismometer (in Greek seismos = earthquake and metero = measure) are used by seismologists to measure and record the size and force of seismic waves. ... Description Role: Earth and Lunar Orbit Crew: 3; CDR, CM pilot, LM pilot Dimensions Height: 36. ...

The mass of the Moon is sufficient to eliminate any voids within the interior, so it is believed to be composed of solid rock throughout. Its low bulk density (~3346 kg m^-3) indicates a low metal abundance. Mass and moment of inertia constraints indicate that the Moon likely has an iron core that is less than about 450 km in radius. Studies of the Moon's physical librations (small perturbations to its rotation) furthermore indicate that the core is still molten. Most planetary bodies and moons have iron cores that are about half the size of the body. The Moon is thus anomalous in possessing a core whose size is only about one quarter of its radius. Moment of inertia, also called mass moment of inertia and, sometimes, the angular mass, (SI units kg m², English units lbs ft2) quantifies the rotational inertia of a rigid body, i. ...

The crust of the Moon is on average about 50 km thick (though this is uncertain by about ±15 km). It is widely believed that the far-side crust is on average thicker than the near side by about 15 km. ^[4]. Seismology has constrained the thickness of the crust only near the Apollo 12 and 14 landing sites. While the initial Apollo-era analyses suggested a crustal thickness of about 60 km at this site, recent reanalyses of this data set suggest a thinner value, somewhere between about 30 and 45 km.

Compared to that of Earth, the Moon has only a very weak external magnetic field. Other major differences are that the Moon does not currently have a dipolar magnetic field (as would be generated by a geodynamo in its core), and the magnetizations that are present are almost entirely crustal in orgin. One hypothesis holds that the crustal magnetizations were acquired early in lunar history when a geodynamo was still operating. The small size of the lunar core, however, is a potential obstacle to this theory. Alternatively, it is possible that on airless bodies such as the Moon, transient magnetic fields could be generated during impact processes. In support of this, it has been noted that the largest crustal magnetizations appear to be located near the antipodes of the largest impact basins. While the Moon does not possess a dipolar magnetic field like the Earth does, some of the returned rocks possess strong magnetizations. Furthermore measurements from orbit show that some portions of the lunar surface are associated with strong magnetic fields. To meet Wikipedias quality standards, this article may require cleanup. ...

Lunar north pole, image of the crater with a possible ice reserve. NASA photo.

Download high resolution version (1000x999, 178 KB) North Pole Region of the Moon as Seen by Clementine Original Caption Released with Image Lunar mosaic of ~1500 Clementine images of the north polar region of the moon. ... Download high resolution version (1000x999, 178 KB) North Pole Region of the Moon as Seen by Clementine Original Caption Released with Image Lunar mosaic of ~1500 Clementine images of the north polar region of the moon. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ...

See also

• Moon
• Lunar geologic timescale
• Lunar meteorites
• Lunar mare
• Transient lunar phenomenon
• Selenography

Bulk silicate composition (estimated wt%) SiO2 44. ... The lunar geologic timescale (or perhaps more properly the selenologic timescale) divides the history of Earths Moon into six generally recognized geologic periods: Copernician Period : 1100 MY to present Eratosthenian Period : 3200 MY to 1100 MY Upper Imbrian Epoch : 3800 MY to 3200 MY Lower Imbrian Epoch : 3850 MY... Lunar Meteorite Allan Hills 81005 A Lunar meteorite is a meteorite that is known to have originated on the Moon. ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... A transient lunar phenomenon (TLP) is a sometimes inexplicable change of color or shape seen on the surface of the moon. ... Selenography is the study of the surface and physical features of the Moon, especially the mapping of the features according to the Moons latitude and longitude. ...

References

• This article draws heavily on the corresponding article in the Spanish-language Wikipedia, which was accessed in the version of 11 October 2005.

Paul D. Spudis is an American geologist and lunar scientist. ... See also: 1997 in literature, other events of 1998, 1999 in literature, list of years in literature. ... See also: 2002 in literature, other events of 2003, 2004 in literature, list of years in literature. ... See also: 1995 in literature, other events of 1996, 1997 in literature, list of years in literature. ...

External links

• Apollo over the Moon: A View from Orbit, edited by Harold Masursky, G. W. Colton, and Farouk El-baz, NASA SP-362.
• Eric Douglass, Geologic Processes on the Moon
• Lunar Sample Information (JSC)
• The Apollo Lunar Surface Journal (NASA)
• Lunar and Planetary Institute: Exploring the Moon
• Clementine Lunar Image Browser
• Ralph Aeschliman Planetary Cartography and Graphics: Lunar Maps
• Lunar Gravity, Topography and Crustal Thickness Archive

The Moon v • d • e
General: Phases of the Moon · Solar eclipse · Lunar eclipse · The Moon's orbit · Near and Far sides of the Moon · Tides
Lunar science: Moon rocks · Geology · Lunar mare · Lunar geologic timescale · Lunar meteorites · KREEP · Giant impact theory
Exploration: Exploration of the Moon · Manned exploration (20th Century)(21st Century) · Robotic exploration · Future missions
See also solar system, natural satellite, and impact craters.

For other moons in the solar system see natural satellite. ... Image File history File links Moon-footer. ... In astronomy, a phase of the Moon is any of the aspects or appearances presented by the Moon as seen from Earth, determined by the portion of the Moon that is visibly illuminated by the Sun. ... Photo taken during the 1999 eclipse. ... An eclipse refers to the phenomenon of one body passing into the shadow cast by another body. ... // Complete orbit The Moon makes a complete orbit about the Earth approximately once every 27. ... The near side of the Moon is the lunar hemisphere that is permanently turned towards the Earth, and as such the side which is always seen. ... Far side of the Moon. ... The tide is the cyclic rising and falling of Earths ocean surface caused by the tidal forces of the Moon and the Sun acting on the Earth. ... Genesis Rock returned by the Apollo 15 mission. ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... The lunar geologic timescale (or perhaps more properly the selenologic timescale) divides the history of Earths Moon into six generally recognized geologic periods: Copernician Period : 1100 MY to present Eratosthenian Period : 3200 MY to 1100 MY Upper Imbrian Epoch : 3800 MY to 3200 MY Lower Imbrian Epoch : 3850 MY... Lunar Meteorite Allan Hills 81005 A Lunar meteorite is a meteorite that is known to have originated on the Moon. ... KREEP stands for potassium (atomic symbol K), rare earth elements (REE), and phosphorus (P). ... The Big Splash The giant impact theory (or Big Splash or Big Whack; cf. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Project Apollo was a series of human spaceflight missions undertaken by the United States of America (NASA) using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961–1975. ... Project Constellation is NASAs current plan for space exploration. ... Pioneer 0 (USA, 1958) - failure - orbiter Pioneer 1 (USA, 1958) - failure - orbiter Pioneer 3 (USA, 1958) - failure - flyby Luna 1 (Soviet Union, 1959) - success - flyby Pioneer 4 (USA, 1959) - partial success - flyby Luna 2 (Soviet Union, 1959) - success - impactor Luna 3 (Soviet Union, 1959) - success - flyby Ranger 3 (USA, 1962... This article, which relates to the Moon, is a stub. ... Major features of the Solar System (not to scale): The Sun, the eight planets, the asteroid belt containing the dwarf planet Ceres, outermost there is the dwarf planet Pluto (the dwarf planet Eris not shown), and a comet. ... Moons of the Solar System scaled to Earths Moon A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ... This article is about impact craters, also known as meteor craters. ...