, Williams, Dr. David R.
, Moon Fact Sheet
,
NASA (National Space Science Data Center)
,
weblink, February 2, 2006
, 2008-12-31,
1,735.97 km }} {{nowrap|(0.273 Earths)}}
| (1)(2)
−12.74 (mean full Moon)(3)| temp_name1 = equator | kelvin>K| mean_temp_1 = 220 K| max_temp_1 = 390 K | 0.3em | (4)}}| min_temp_2 = 70 K| mean_temp_2 = 130 K| max_temp_2 = 230 K | (5) | −7 | Pascal (unit)>Pa (day)
10
−10 Pa (night)| atmosphere_composition = H, He, Na, K, Rn, Ar| atmosphere = yes
lunar)}}{{FixBunching|end}}The Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is {{Convert|384403|km}}, about thirty times the diameter of the Earth. The common centre of mass of the system (the barycentre) is located at about {{Convert|1700|km}}—a quarter the Earth's radius—beneath the surface of the Earth. The Moon makes a complete orbit around the Earth every 27.3 days | (6) (the
orbital period), and the periodic variations in the geometry of the Earth–Moon–
Sun system are responsible for the
phases of the Moon, which repeat every 29.5 days
(7) (the
synodic period).The Moon's diameter is {{Convert|3474|km}},
(8) a little more than a quarter of Earth's. Thus, the Moon's
surface area is less than a
tenth of the Earth (about a quarter of Earth's land area), and its volume is about 2 percent that of Earth. The pull of
gravity at its surface is about 17 percent of that at the Earth's surface.The Moon is the only
celestial body on which human beings have made a manned
landing. While the
Soviet Union's
Luna programme was the first to reach the Moon with unmanned
spacecraft, the
United States' NASA Apollo program achieved the only manned missions to date, beginning with the first manned lunar mission by
Apollo 8 in 1968, and six manned lunar landings between 1969 and 1972–the first being
Apollo 11 in 1969. Human exploration of the Moon temporarily ceased with the conclusion of the Apollo program, although a few robotic landers and orbiters have been sent to the Moon since that time. The U.S. had committed to return to the Moon by 2018,
(9)(10)(11) however that commitment has been put into jeopardy by the proposed 2011 budget, which will cancel
Constellation, NASA's project to send humans back to the moon by 2020. On November 13, 2009, NASA announced the discovery of proof that water exists on the Moon, based on data obtained from its
LCROSS lunar impact mission.
(12)Name and etymology
The proper
English name for Earth's natural satellite is, simply, the Moon (capitalized).
(13)(14) Moon is a
Germanic word, related to the Latin and Ancient Greek μήνας (mēnas) both meaning month, and Μήνη (Mēnē) (alternate name for Selēnē in Ancient Greek).
(15)(16) It is ultimately a derivative of the
Proto-Indo-European root
me-, also represented in
measure(17) Subsequently, these objects were given distinct names to avoid confusion.
The Moon is occasionally referred to by its Latin name , primarily in science fiction.
Lunar surface
Two sides of the Moon
{{See also|Topography of the Moon}}{{multiple image
| align = right
| width = 170
| image1 = Moon PIA00302.jpg
| alt1 = The dark irregular mare lava plains are most prominent in the fully illuminated disk. A single bright star of ejecta, with rays stretching a third of the way across the disk, emblazons the lower centre: this is the crater Tycho.
| caption1 =
Near side of the Moon | image2 = Moon PIA00304.jpg
| alt2 = In contrast, the full disk is near-featureless, with no dark mare and a uniform grey surface. Many bright dots of impact craters are randomly arranged on the disk, almost all overlapping others.
| caption2 =
Far side of the Moon
}}
missing image!
- MoonTopoGeoidUSGS.jpg -
alt=The near side has flat, deeper mares and southern highlands; the far side has a huge southern circular depression, with a similarly sized, more irregular high region to its north-east. The relief on the far side is much more extreme than that on the near side.|Topography of the Moon, referenced to the lunar geoid.
The Moon is in
synchronous rotation, which means it rotates about its axis in about the same time it takes to
orbit the Earth. This results in it nearly always keeping the same face turned towards the Earth. The Moon used to rotate at a faster rate, but early in its history, its rotation slowed and became
locked in this orientation as a result of
frictional effects associated with
tidal deformations caused by the Earth.
(18) The side of the Moon that faces Earth is called the
near side, and the opposite side the
far side. The far side is often inaccurately called the "dark side," but in fact, it is illuminated exactly as often as the near side: once per lunar day, during the new Moon phase we observe on Earth when the near side is dark.
(19) The far side of the Moon was first photographed by the Soviet probe
Luna 3 in 1959.
(20) One distinguishing feature of the far side is its almost complete lack of
maria.
(21)The
topography of the Moon has been measured by the methods of laser altimetry and stereo image analysis, most recently from data obtained during the
Clementine mission. The most visible topographic feature is the giant far side
South Pole-Aitken basin, which possesses the lowest elevations of the Moon. The highest elevations are found just to the north-east of this basin, and it has been suggested that this area might represent thick
ejecta deposits that were emplaced during an oblique South Pole-Aitken basin impact event. Other large impact basins, such as
Imbrium,
Serenitatis,
Crisium,
Smythii, and
Orientale, also possess regionally low elevations and elevated rims. Another distinguishing feature of the Moon's shape is that the elevations are on average about 1.9 km higher on the far side than the near side.
(22) compared with about 31% on the near side.
(23)(24) Several provinces containing
shield volcanoes and volcanic
domes are found within the near side maria.
(25)Terrae
The lighter-colored regions of the Moon are called
terrae, or more commonly just
highlands, since they are higher than most maria. Several prominent mountain ranges on the near side are found along the periphery of the giant
impact basins, many of which have been filled by mare basalt. These are hypothesized to be the surviving remnants of the impact basin's outer rims.
(26) In contrast to the Earth, no major lunar mountains are believed to have formed as a result of tectonic events.
(27)From images taken by the
Clementine mission in 1994, it appears that four mountainous regions on the rim of the 73 km-wide
Peary crater at the Moon's north pole remain illuminated for the entire lunar day. These
peaks of eternal light are possible because of the Moon's extremely small axial tilt to the
ecliptic plane. No similar regions of eternal light were found at the south pole, although the rim of
Shackleton crater is illuminated for about 80% of the lunar day. Other consequences of the Moon's small axial tilt are regions that remain in permanent shadow at the bottoms of many polar craters.
(28)Impact craters
missing image!
- Moon-craters.jpg -
alt=A grey, many-ridged surface viewed obliquely from an indeterminate height: there is no sense of scale. The largest feature is a circular ringed structure with high walled sides and a lower central peak: the entire surface out to the horizon is filled with similar structures that are smaller and overlapping.|Lunar crater Daedalus on the Moon's far side
The surface of Earth's Moon is marked by
impact craters
(29) which form when asteroids and comets collide with the lunar surface. There are about half a million craters with diameters greater than 1 km on the Moon.{{Citation needed|date=September 2009}} Since impact craters accumulate at a nearly constant rate, the number of craters per unit area superposed on a geologic unit can be used to estimate the age of the surface (see
crater counting). The lack of an atmosphere, weather and recent geological processes ensures that many of these craters have remained relatively well preserved in comparison to those on Earth.The largest crater on the Moon, which also has the distinction of being one of the largest known craters in the Solar System,
(30) is the
South Pole-Aitken basin. It is on the far side, between the South Pole and equator, and is some 2,240 km in diameter and 13 km in depth.
(31) Prominent impact basins on the near side include
Imbrium,
Serenitatis,
Crisium, and
Nectaris.
Regolith
Blanketed on top of the Moon's crust is a highly
comminuted (broken into ever smaller particles) and "impact gardened" surface layer called
regolith. Since the regolith forms by impact processes, the regolith of older surfaces is generally thicker than for younger surfaces. In particular, it has been estimated that the regolith varies in thickness from about 3–5 m in the maria, and by about 10–20 m in the highlands.
(32) Beneath the finely comminuted regolith layer is what is generally referred to as the
megaregolith. This layer is many kilometres thicker and comprises highly fractured bedrock.
(33)Astronauts have reported that the
dust from the surface felt like snow and smelled like spent
gunpowder.
(34) The dust is mostly made of
silicon dioxide glass (SiO
2), most likely created from the meteors that have crashed into the Moon's surface. It also contains
calcium and
magnesium.
Presence of water
missing image!
- Moon_South_Pole.jpg -
thumbnail|alt=A full twenty degrees of latitude of the Moon's disk, northwards of the South Pole, completely covered in the overlapping circles of craters. The illumination angles are from all directions, keeping almost all the crater floors in sunlight, but a set of merged crater floors right at the south pole are completely shadowed.|Lunar south pole as imaged by Clementine
The continuous bombardment of the Moon by
comets and
meteoroids has most likely added small amounts of water to the lunar surface. If so, sunlight would split much of this water into its constituent elements of hydrogen and oxygen, both of which would ordinarily escape into space over time because of the Moon's weak gravity. However, because of the slightness of the axial tilt of the Moon's spin axis to the ecliptic plane—only 1.5°—some deep craters near the poles never receive direct light from the Sun and are thus in permanent shadow (see
Shackleton crater). Water molecules that ended up in these craters could be stable for long periods of time.Clementine has mapped craters at the lunar south pole
(35) that are shadowed in this way, and computer simulations suggest that up to 14,000 km² might be in permanent shadow.
(36) Estimate for the quantity of water on the Moon is 32 ounces per short ton (1 kg/Mg) of the top layer of Moon's surface.Water ice can be mined and then split into its constituent hydrogen and oxygen atoms by means of nuclear generators or electric power stations equipped with solar panels. The presence of usable quantities of water on the Moon is an important factor in rendering
lunar habitation cost-effective, since transporting water from Earth would be prohibitively expensive. However, recent observations made with the
Arecibo planetary radar suggest that some of the near-polar Clementine radar data that were previously interpreted as indicating water ice might instead be a result of rocks ejected from young impact craters.
(37) The question of how much water there is on the Moon has not been resolved.In July 2008, small amounts of water were found in the interior of volcanic pearls from the Moon (brought to Earth in 1971 by the Apollo 15 astronauts).
(38)(39)On September 24, 2009, the
Indian Space Research Organisation (
ISRO) reported that their first lunar mission,
Chandrayaan-1 using
NASA's
Moon Mineralogy Mapper, found evidence of large quantities of water on the Moon's surface, and that water is still presently being formed.
(40)(41) The instrument observed an
absorption line in the
spectrum of sunlight reflected from the Moon, indicating that light of a particular wavelength (around 2.8
micrometres) is being absorbed more readily than other nearby wavelengths. The position and shape of the line indicate the absorption is due to water. A nearby line also revealed the presence of the closely-related molecule
hydroxyl, which consists of an oxygen atom with a single hydrogen atom. The exact abundance of water was not determined, but the team believed it could be as high as 1,000
parts per million in the top layer of Lunar soil.On November 13, 2009, NASA announced the results of the
Lunar Crater Observation and Sensing Satellite, saying that "not just water, but lots of water" had been found by the mission near the southern pole.
(42)Physical characteristics
Internal structure
right|450px|alt=A circle divided into four rings and a centre. The outermost line is 'anorthositic crust'. The outer two rings, the upper and middle mantle, are equal in thickness, and occupy two-thirds of the circle's area. Going inwards, the lower mantle is '~587 km radius, zone of partial melt'; the fluid outer core is '~350 km radius', and these rings are each half as thick as each of the mantle rings. The solid inner core is '~160 km radius, assuming 10% of the core has crystallized'.|Schematic of the internal structure of the MoonThe Moon is a
differentiated body, being composed of a geochemically distinct
crust,
mantle, and
core. This structure is hypothesized to have resulted from the
fractional crystallization of a
magma ocean shortly after its formation, at about 4.4 billion years ago
(43). The energy required to melt the outer portion of the Moon is commonly attributed to a
giant impact event that is postulated to have formed the Earth-Moon system, and the subsequent reaccretion of material in Earth orbit. Crystallization of this magma ocean would have created a
mafic mantle and a
plagioclase-rich crust (see
Origin and geologic evolution below).Geochemical mapping from orbit implies that the crust of the Moon is largely
anorthositic in composition,
(44) consistent with the magma ocean hypothesis. In terms of elements, the crust is composed primarily of
oxygen (41% to 46% by mass),
silicon (21%),
magnesium (6%),
iron (13%),
calcium (8%), and
aluminium (7%).
(45)(46) Based on geophysical techniques, its thickness is estimated to be on average about 50 km.
(47)Partial melting within the mantle of the Moon caused the eruption of mare basalts on the lunar surface. Analyses of these basalts indicate that the mantle is composed predominantly of the minerals
olivine,
orthopyroxene and
clinopyroxene, and that the lunar mantle is more iron rich than that of the Earth. Some lunar basalts contain high abundances of
titanium (present in the mineral
ilmenite), suggesting that the mantle is highly heterogeneous in composition. Moonquakes have been found to occur deep within the mantle of the Moon about a thousand kilometres below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth.
(48)Gravity field
The gravitational field of the Moon has been determined through tracking of radio signals emitted by orbiting spacecraft. The principle used depends on the
Doppler effect, whereby the spacecraft acceleration in the line-of-sight direction can be determined by means of small shifts in frequency of the radio signal, and the distance from the spacecraft to a station on Earth. However, because of the Moon's
synchronous rotation it is not possible to track spacecraft much over the (wiktionary:Limb|limb)s of the Moon, and the farside gravity field is thus only poorly characterised.
(49)The major characteristic of the Moon's gravitational field is the presence of
mascons, which are large positive gravitational anomalies associated with some of the giant
impact basins.
(50) These anomalies greatly influence the orbit of spacecraft about the Moon, and an accurate gravitational model is necessary in the planning of both manned and unmanned missions. The mascons are in part due to the presence of dense mare basaltic lava flows that fill some of the impact basins. However, lava flows by themselves cannot explain the entirety of the gravitational signature, and uplift of the crust-mantle interface is required as well. Based on
Lunar Prospector gravitational models, it has been suggested that some mascons exist that do not show evidence for mare basaltic volcanism.
(51) The huge expanse of mare basaltic volcanism associated with
Oceanus Procellarum does not possess a positive gravitational anomaly.
Magnetic field
The Moon has an external
magnetic field of the order of one to a hundred
nanoteslas—less than one-hundredth that of the
Earth, which is 30–60 microteslas. 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 origin.
(52) 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 an airless body such as the Moon, transient magnetic fields could be generated during large impact events. In support of this, it has been noted that the largest crustal magnetizations appear to be located near the
antipodes of the giant impact basins. It has been proposed that such a phenomenon could result from the free expansion of an impact generated plasma cloud around the Moon in the presence of an ambient magnetic field.
(53)Atmosphere
The Moon has an atmosphere so thin as to be almost negligible, with a total atmospheric mass of less than 10
4 kg.
(54) The effective surface pressure of this small mass is around 3{{esp|−15}}
atm (0.3
nPa).
(55) This pressure varies with the diurnal moon cycle. One source of its atmosphere is
outgassing—the release of gases such as
radon that originate by
radioactive decay processes within the crust and mantle.
(56) Another important source is generated through the process of
sputtering, which involves the bombardment of micrometeorites, solar wind ions, electrons, and sunlight.
(57) Argon-40 (
40Ar),
helium-4 (
4He),
oxygen (O
2) and/or
methane (CH
4),
nitrogen (N
2) and/or
carbon monoxide (CO), and
carbon dioxide (CO
2) were detected by in-situ detectors placed by the Apollo astronauts.
(58)Surface temperature
During the lunar day, the surface temperature averages 107 °C, and during the lunar night, it averages −153 °C.
(59)The Moon has the coldest place in the Solar System measured by a spacecraft.NASA's
Lunar Reconnaissance Orbiter has used its Diviner instrument to probe the insides of permanently shadowed craters on Earth's satellite.
[WEB, September 17, 2009,weblink Diviner News
], UCLA, 2010-03-17, It found mid-winter, night-time surface temperatures inside the coldest craters in the northern polar region can dip as low as minus 249 °C (26 kelvins). The Diviner instrument observed the lowest summer temperatures in the darkest craters at the southern pole to be about 35 K (−238 °C); but in the north, close to the winter solstice the instrument recorded a temperature of just 26 K on the south-western edge of the floor of
Hermite Crater.
Origin and geologic evolution
Formation
Several mechanisms have been suggested for the Moon's formation. The formation of the Moon is hypothesized to have occurred 4.527 ± 0.010 billion years ago, about 30–50 million years after the origin of the Solar System.(60)
- Fission hypothesis : Early speculation proposed that the Moon broke off from the Earth's crust because of centrifugal forces, leaving a basin—presumed to be the Pacific Ocean—behind as a scar.(61) This idea, however, would require too great an initial spin of the Earth and would have resulted in the Moon's orbit following Earth's equatorial plane rather than its current path.(62)
- Capture hypothesis : Other speculation has centered on the Moon being formed elsewhere and subsequently being captured by Earth's gravity.(63) However, the conditions conjectured necessary for such a mechanism to work, such as an extended atmosphere of the Earth to dissipate the energy of the passing Moon, are improbable.
- Co-formation hypothesis : The co-formation hypothesis proposes that the Earth and the Moon formed together at the same time and place from the primordial accretion disk. The Moon would have formed from material surrounding the proto-Earth, similar to the formation of the planets around the Sun. Some suggest that this hypothesis fails to adequately explain the depletion of metallic iron in the Moon.
A major deficiency in all these hypotheses is that they cannot readily account for the high
angular momentum of the Earth–Moon system.
(64)
- Giant impact hypothesis
- The prevailing hypothesis today is that the Earth–Moon system formed as a result of a giant impact. A Mars-sized body (labelled "Theia") is hypothesized to have hit the proto-Earth, blasting sufficient material into orbit around the proto-Earth to form the Moon through accretion.(65) Unresolved questions regarding this theory concern the determination of the relative sizes of the proto-Earth and Theia and of how much material from these two bodies formed the Moon. Recent oxygen isotope composition analysis of the Moon shows its oxygen isotope composition is more similar to the Earth's than this hypothesis would suggest.(66)
Lunar magma ocean
As a result of the large amount of energy converted during both the giant impact event and the subsequent reaccretion of material in Earth orbit, it is commonly hypothesized that a large portion of the Moon was once initially molten. The molten outer portion of the Moon at this time is referred to as a magma ocean, and estimates for its depth range from about 500 km to the entire radius of the Moon.(67) and the youngest eruptions, based on the method of crater counting, are hypothesized to have occurred only 1.2 billion years ago.(68)There has been controversy over whether features on the Moon's surface undergo changes over time. Some observers have claimed that craters either appeared or disappeared, or that other forms of transient phenomena had occurred. Today, many of these claims are thought to be illusory, resulting from observation under different lighting conditions, poor astronomical seeing, or the inadequacy of earlier drawings. Nevertheless, it is known that the phenomenon of outgassing does occasionally occur, and these events could be responsible for a minor percentage of the reported lunar transient phenomena. Recently, it has been suggested that a roughly 3 km diameter region of the lunar surface was modified by a gas release event about a million years ago.(69)(70)Moon rocks
Moon rocks fall into two main categories, based on whether they underlie the lunar highlands (terrae) or the maria. The lunar highlands rocks are composed of three suites: the ferroan anorthosite suite, the magnesian suite, and the alkali suite (some consider the alkali suite to be a subset of the mg-suite). The ferroan anorthosite suite rocks are composed almost exclusively of the mineral anorthite (a calic plagioclase feldspar), and are hypothesized to represent plagioclase flotation cumulates of the lunar magma ocean. The ferroan anorthosites have been dated using radiometric methods to have formed about 4.4 billion years ago.(71)(72)Orbit and relationship to Earth
{{Mergefrom|Earth and Moon|date=February 2010}}missing image!
- EarthAndMoon.jpg -
right|alt=In a set of four images, the dark shadowed disk of the Moon moves from left to right across the face of the blue and brown quarter-phase Earth, covering only a small part of the cloud-swirled semicircle.|Comparative sizes of Earth and the Moon, as seen from Deep Impact, 50 million km distant
File:Lunar libration with phase2.gif|thumb|right|250px|alt=Over the course of a month, the disk of the Moon, imaged each day and with the shadow of its phases moving day-by-day across the surface, makes a small gentle wobble, slightly changing the boundaries of the visible half of the Moon's surface.|Lunar librationlibrationThe Moon makes a complete orbit around the Earth with respect to the fixed stars about once every 27.3 days(73) As a result of the conservation of angular momentum, the slowing of Earth's rotation is accompanied by an increase of the mean Earth-Moon distance of about 3.8 m per century, or 3.8 cm per year.(74)The Moon is exceptionally large relative to the Earth, being a quarter the diameter of the planet and 1/81 its mass. However, the Earth and Moon are still commonly considered a planet-satellite system, rather than a double-planet system, since the common centre of mass of the system (the barycentre) is located about 1,700 km beneath the surface of the Earth, or about a quarter of the Earth's radius. The surface of the Moon is less than one-tenth that of the Earth, and only about a quarter the size of the Earth's land area (or about as large as Russia, Canada, and the U.S. combined).The current obliquity of the Moon means that the Sun never rises above 1.85° at the poles. The axial tilt of the Moon has remained at its present orientation for the past two billion years, allowing the craters at the poles to remain in permanent shadow for that length of time.[JOURNAL
], Margot, J. L.; Campbell, D. B.; Jurgens, R. F.; Slade, M. A.
, Topography of the Lunar Poles from Radar Interferometry: A Survey of Cold Trap Locations
, Science, 1999-06-04, 284
, 5420, 1658–1660
, 10.1126/science.284.5420.1658
, 10356393, Before that point, the Moon had much larger values for its obliquity, possibly reaching angles as high as 77° for periods of several hundred thousand years.
(75)
missing image!
- Speed of light from Earth to Moon.gif -
alt=A line is emitted from the full Earth, and moves across dark space until it reaches the considerably smaller full Moon, where it shortens and disappears into the Moon's surface.|The relative sizes and separation of the Earth–Moon system are shown to scale above. The beam of light is depicted travelling between the Earth and the Moon in the same time it takes light to scale the real distance between them: 1.255 seconds at its mean orbital distance. The light beam helps provide the sense of scale of the Earth-Moon system relative to the Sun, which is 8.28 light-minutes away (photosphere to Earth surface).
{{clear}}Ocean tides
Earth's ocean tides are initiated by the tidal force (a gradient in intensity) of Moon's gravity and are magnified by a host of effects in Earth's oceans. (Earth's ocean tides are also significantly affected by the Sun; the gravitational attraction of the Sun on the Earth's oceans is almost half that of the Moon, and this interplay results in "spring tides" and "neap tides".) The gravitational tidal force arises because the side of Earth facing the Moon (nearest it) is attracted more strongly by the Moon's gravity than is the center of the Earth and—even less so—the Earth's far side. The gravitational tide stretches the Earth's oceans into an ellipse with the Earth in the center. The effect takes the form of two bulges—elevated sea level relative to the Earth; one nearest the Moon and one farthest from it. Since these two bulges rotate around the Earth once a day as it spins on its axis, ocean water is continuously rushing towards the ever-moving bulges. The effects of the two bulges and the massive ocean currents chasing them are magnified by an interplay of other effects; namely frictional coupling of water to Earth's rotation through the ocean floors, inertia of water's movement, ocean basins that get shallower near land, and oscillations between different ocean basins. The magnifying effect is a bit like water sloshing high up the sloped end of a bathtub after a relatively small disturbance of one's body in the deep part of the tub.Gravitational coupling between the Moon and the ocean bulge nearest the Moon affects its orbit. The Earth rotates on its axis in the very same direction, and roughly 27 times faster, than the Moon orbits the Earth. Thus, frictional coupling between the sea floors and ocean waters, as well as water's inertia, drags the peak of the near-Moon tidal bulge slightly forward of the imaginary line connecting the centers of the Earth and Moon. From the Moon's perspective, the center of mass of the near-Moon tidal bulge is perpetually slightly ahead of the point about which it is orbiting. Precisely the opposite effect occurs with the bulge farthest from the Moon; it lags behind the imaginary line. However, it is 12,756 km farther away and has slightly less gravitational coupling to the Moon. Consequently, the Moon is constantly being gravitationally attracted forward in its orbit about the Earth. This gravitational coupling drains kinetic energy and angular momentum from the Earth's rotation (see also, Day and Leap second). In turn, angular momentum is added to the Moon's orbit, which lifts the Moon into a higher orbit with a longer period. The effect on the Moon's orbital radius is a small one, just 0.10 ppb/year, but results in a measurable 3.82 cm annual increase in the Earth-Moon distance.Eclipses
{{multiple image
| width = 150
| footer = From the Earth, the Moon and Sun appear the same size. From a satellite in an Earth-trailing orbit, the Moon appears smaller than the Sun.
| image1 = Solar eclips 1999 4 NR.jpg
| alt1 = The fiercely bright disk of the Sun is completely obscured by the exact fit of the disk of the dark, non-illuminated Moon, leaving only the radial, fuzzy, glowing coronal filaments of the Sun visible around the edge.
| caption1 = The 1999 solar eclipse
| image2 = STEREO-B solar eclipse.jpg
| alt2 = The bright disk of the Sun, showing many coronal filaments, flares and grainy patches in the wavelength of this image, is partly obscured by a small dark disk: here, the Moon covers less than a fifteenth of the Sun.
| caption2 = The Moon passing in front of the Sun, from the
STEREO-B spacecraft.
(78)
Observation
{{See also|Lunar phase|Earthshine|Observing the Moon|Moon illusion}}During its brightest phase, at "full Moon", the Moon has an apparent magnitude of about −12.7. By comparison, the Sun has an apparent magnitude of −26.7. When the Moon is in a quarter phase, its brightness is not half of a full Moon, but only about a tenth. This is because the lunar surface is not a perfect Lambertian reflector. When the Moon is full the opposition effect makes it appear brighter, but away from full there are shadows projected onto the surface which diminish the amount of reflected light.(File:Phases of the Moon.png|thumb|600px|right|alt=The orbital positions of the Moon and Earth, with illumination from the right. As the Moon travels anticlockwise around the Earth, each geometric arrangement of Moon, Earth and illumination are matched to the corresponding phase of the Moon: dark circle, sliver of a crescent, half circle, three-quarters circle, fully illuminated circle, and the same in reverse.|The phases of the Moon in their order of appearance: New Moon through Crescent, First Quarter, and Gibbous to reach Full Moon. This is followed by Gibbous, Last Quarter and Crescent to complete full circle at the New Moon again.)On average, the Moon covers an area of 0.21078 square degrees on the night sky.(83)The Moon does appear larger when close to the horizon, but this is a purely psychological effect: the Moon illusion.The Moon appears as a relatively bright object in the sky, in spite of its low albedo. The Moon is about the poorest reflector in the solar system and reflects only about 7% of the light incident upon it (about the same proportion as is reflected by a lump of coal). However, the Moon is not a Lambertian scatterer and reflects more light back towards the Sun (albedo of 13.6%(84) It also has the effect of making the edges of a full Moon seem about as bright as the centre. Besides this, color constancy in the visual system recalibrates the relations between the colours of an object and its surroundings, and since the surrounding sky is comparatively dark the sunlit Moon is perceived as a bright object.The highest altitude of the Moon on a day varies and has nearly the same limits as the Sun. It also depends on the Earth season and lunar phase, with the full Moon being highest in winter. Moreover, the 18.6 year nodes cycle also has an influence, as when the ascending node of the lunar orbit is in the vernal equinox, the lunar declination can go as far as 28° each month (which happened most recently in 2006). This results that the Moon can go overhead on latitudes up to 28 degrees from the equator (e.g. Florida, Canary Islands or in the southern hemisphere Brisbane). Slightly more than 9 years later (next time in 2015) the declination reaches only 18° N or S each month.The orientation of the Moon's crescent also depends on the latitude of the observation site. Close to the equator, an observer can see a boat Moon.(85)Like the Sun, the Moon can cause atmospheric effects, including a 22° halo ring, and the smaller coronal rings seen more often through thin clouds.Exploration
{{See also|Robotic exploration of the Moon|List of current and future lunar missions|Colonization of the Moon}}missing image!
- NASA-Apollo8-Dec24-Earthrise.jpg -
right|alt=The small blue-white semicircle of the Earth, almost glowing with colour in the blackness of space, rising over the limb of the desolate, cratered surface of the Moon from lunar orbit. Africa is at the sunset terminator, both Americas are under cloud, and Antarctica is at the left end of the terminator.|Earth as viewed from the Moon during the Apollo 8 mission, Christmas Eve, 1968
The first leap in lunar observation was prompted by the invention of the telescope. Galileo Galilei made good use of this new instrument and observed mountains and craters on the Moon's surface.First direct exploration: 1959-1980s
The Cold War-inspired space race between the Soviet Union and the U.S. led to an acceleration of interest in the Moon. Unmanned probes, both flyby and impact/lander missions, were sent once allowed by launcher capabilities. The Soviet Union's Luna program was the first to reach the Moon with unmanned spacecraft. The first man-made object to escape Earth's gravity and pass near the Moon was Luna 1, the first man-made object to impact the lunar surface was Luna 2, and the first photographs of the normally occluded far side of the Moon were made by Luna 3, all in 1959. The first spacecraft to perform a successful lunar soft landing was Luna 9 and the first unmanned vehicle to orbit the Moon was Luna 10, both in 1966.(86) Neil Armstrong became the first person to walk on the Moon as the commander of the American mission Apollo 11 by first setting foot on the Moon at 02:56 UTC on July 21, 1969. The American Moon landing and return was enabled by considerable technological advances in the early 1960s, in domains such as ablation chemistry and atmospheric re-entry technology.Today, {{age in years and days|1972|12|14}} have passed since Eugene Cernan and Harrison Schmitt, as part of the mission Apollo 17, left the surface of the Moon on December 14, 1972 (Cernan being the last to enter the LM): no one has set foot on it since.Scientific instrument packages were installed on the lunar surface during all the Apollo missions. Long-lived instrument stations, including heat flow probes, seismometers, and magnetometers, were installed at the Apollo 12, 14, 15, 16, and 17 landing sites. Direct transmission of data to Earth concluded in late 1977 due to budgetary considerations,(87)(88) but as the stations' lunar laser ranging corner-cube retroreflector arrays are passive instruments, they are still being used. Ranging to the stations is routinely performed from earth-based stations with an accuracy of a few centimetres, and data from this experiment are being used to place constraints on the size of the lunar core.(89)From the mid-1960s to the mid-1970s, there were 65 instances of artificial objects reaching the Moon (both manned and robotic, with ten in 1971 alone); the last was Luna 24, in 1976. Only 18 of these were controlled Moon landings, with nine completing a round trip from Earth and returning rock samples. The Soviet Union then turned its primary attention to Venus and space stations, and the U.S. to Mars and beyond.{{fact}}Current era: 1990-present
Post-Apollo and Luna, many more countries have become involved in direct exploration of the Moon.In 1990, Japan orbited the Moon with the Hiten spacecraft, becoming the third country to place a spacecraft into lunar orbit. The spacecraft released a smaller probe, Hagormo, in lunar orbit, but the transmitter failed, preventing further scientific use of the mission.In 1994, the U.S. sent the joint Defense Department/NASA spacecraft Clementine to lunar orbit. This mission obtained the first near-global topographic map of the Moon, and the first global multispectral images of the lunar surface. This was followed by the Lunar Prospector mission in 1998. The neutron spectrometer on Lunar Prospector indicated the presence of excess hydrogen at the lunar poles, which is likely to have been caused by the presence of water ice in the upper few meters of the regolith within permanently shadowed craters. On January 14, 2004, U.S. President George W. Bush called for a plan to resume manned missions to the Moon by 2020 (see Vision for Space Exploration).(90) NASA is now planning for the construction of a permanent outpost at one of the lunar poles.(91) The European spacecraft Smart 1 was launched September 27, 2003 and was in lunar orbit from November 15, 2004 to September 3, 2006.China has expressed ambitious plans for exploring the Moon and has started the Chang'e program for lunar exploration, successfully launching its first spacecraft, Chang'e-1, on October 24, 2007. On September 14, 2007 the Japan Aerospace Exploration Agency launched SELENE, also known as Kaguya, a lunar orbiter fitted with a high-definition camera and two small satellites.(92)On October 22, 2008 India launched the Chandrayaan I (a Sanskrit word meaning 'Moon-craft') lunar orbiter. The country plans to launch Chandrayaan II in 2010 or 2011, which is slated to include a robotic lunar rover, and has also expressed its hope for a manned mission to the Moon by 2020.(93)The U.S. co-launched the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite (LCROSS) on June 18, 2009. Russia also announced intentions to resume its previously frozen project Luna-Glob, consisting of an unmanned lander and orbiter, which is slated to land in 2012.(94)The Google Lunar X Prize, announced September 13, 2007, hopes to boost and encourage privately funded lunar exploration. The X Prize Foundation is offering anyone US$20 million who can land a robotic rover on the Moon and meet other specified criteria.{{fact}}Human understanding
{{See also|Moon in art and literature|Lunar calendar|Lunar deity|Lunar effect|Blue moon}}missing image!
- Moon by Johannes hevelius 1645.PNG -
alt=On an open folio page is a carefully drawn and coloured disk of the full Moon, delineating the dark mare and many large impact craters. In the upper corners of the page are inscribed waving banners held aloft by pairs of winged cherubs. In the lower left page corner a cherub assists another to measure distances with a pair of compasses; in the lower right corner a cherub views the main map through a handheld telescope, while another, kneeling, peers at the map from over a low cloth-draped table.|Map of the Moon by Johannes Hevelius from his Selenographia (1647)
The Moon has been the subject of many works of art and literature and the inspiration for countless others. It is a motif in the visual arts, the performing arts, poetry, prose and music. A 5000-year-old rock carving at Knowth, Ireland may represent the Moon, which would be the earliest depiction discovered.(95) In many prehistoric and ancient cultures, the Moon was thought to be a deity or other supernatural phenomenon, and astrological views of the Moon continue to be propagated today.In Mesopotamia, Babylonian astronomers by the early first millenium BC had discovered a repeating 18-year cycle of lunar eclipses. They had also known by this time that 19 solar years is about equal to 235 lunar months. In the 2nd century BC, Seleucus of Seleucia correctly theorized that tides were caused by the Moon, although he believed that the interaction was mediated by the Earth's atmosphere. According to Strabo (1.1.9), Seleucus was the first to state that the tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun.(96)Among the first in the Western world to offer a scientific explanation for the Moon was the Greek philosopher Anaxagoras (d. 428 BC), who reasoned that the Sun and Moon were both giant spherical rocks, and that the latter reflected the light of the former. His atheistic view of the heavens was one cause for his imprisonment and eventual exile.(97) In Aristotle's (384–322 BC) description of the universe, the Moon marked the boundary between the spheres of the mutable elements (earth, water, air and fire), and the imperishable stars of aether. This separation was held to be part of Aristotelian physics for many centuries after.(98) Aristarchus went a step further and computed the distance from Earth, together with its size, obtaining a value of 20 times the Earth radius for the distance (the real value is 60; the Earth radius was roughly known since Eratosthenes).During the Warring States of China, astronomer Shi Shen (fl. 4th century BC) gave instructions for predicting solar and lunar eclipses based on the relative positions of the Moon and Sun.(99) Although the Chinese of the Han Dynasty (202 BC–202 AD) believed the Moon to be energy equated to qi, their 'radiating influence' theory recognized that the light of the Moon was merely a reflection of the Sun (mentioned by Anaxagoras above).(100) This was supported by mainstream thinkers such as Jing Fang (78–37 BC) and Zhang Heng (78–139 AD), but it was also opposed by the influential philosopher Wang Chong (27–97 AD).(101) These assertions were supported by Shen Kuo (1031–1095) of the Song Dynasty (960–1279) who created an allegory equating the waxing and waning of the Moon to a round ball of reflective silver that, when doused with white powder and viewed from the side, would appear to be a crescent.(102) He also noted that the reason for the Sun and Moon not eclipsing every time their paths met was because of a small obliquity in their orbital paths.(103) Using these observations, he estimated the Moon's diameter as 3,037 km (equivalent to 1,519 km radius) and its distance from the Earth as 215,209 miles, which come close to the currently accepted values.(104) In 1021, the Islamic physicist, Alhazen, accurately explained the Moon illusion in the Book of Optics, which stated that judging the distance of an object depends on there being an uninterrupted sequence of intervening bodies between the object and the observer. With the Moon, there are no intervening objects, therefore since the size of an object depends on its observed distance, which is in this case inaccurate, the Moon appears larger on the horizon. Through Alhazen's work, the Moon illusion gradually came to be accepted as a psychological phenomenon.(105) He also investigated moonlight, which he proved through experimentation that it originates from sunlight and correctly concluded that it "emits light from those portions of its surface which the sun's light strikes."(106)By the Middle Ages, before the invention of the telescope, an increasing number of people began to recognise the Moon as a sphere, though many believed that it was "perfectly smooth".(107) In 1609, Galileo Galilei drew one of the first telescopic drawings of the Moon in his book and noted that it was not smooth but had mountains and craters. Later in the 17th century, Giovanni Battista Riccioli and Francesco Maria Grimaldi drew a map of the Moon and gave many craters the names they still have today.On maps, the dark parts of the Moon's surface were called maria (singular mare) or seas, and the light parts were called terrae or continents.The possibility that the Moon contains vegetation and is inhabited by selenites was seriously considered by major astronomers even into the first decades of the 19th century. The contrast between the brighter highlands and darker maria create the patterns seen by different cultures as the Man in the Moon, the rabbit and the buffalo, among others.In 1835, the Great Moon Hoax fooled some people into thinking that there were exotic animals living on the Moon.(108) Almost at the same time however (during 1834–1836), Wilhelm Beer and Johann Heinrich Mädler were publishing their four-volume and the book in 1837, which firmly established the conclusion that the Moon has no bodies of water nor any appreciable atmosphere.Legal status
Although several pennants of the Soviet Union were scattered by Luna 2 in 1959 and by later landing missions, and U.S. flags have been symbolically planted on the Moon, no nation currently claims ownership of any part of the Moon's surface. Russia and the U.S. are party to the Outer Space Treaty, which places the Moon under the same jurisdiction as international waters (). This treaty also restricts the use of the Moon to peaceful purposes, explicitly banning military installations and weapons of mass destruction.(109)A second treaty, the Moon Treaty, was proposed to restrict the exploitation of the Moon's resources by any single nation, but it has not been signed by any of the space-faring nations. Several individuals have made claims to the Moon in whole or in part, although none of these are generally considered credible.(110)See also
{{sisterlinks|Moon}}
Notes
-
1,737.10 km }} {{nowrap|(0.273 Earths)}} | 3.793{{esp | (0.074 Earths)}} | 2.195 8{{esp | 1 E+9 m³>km³ }} {{nowrap|(0.020 Earths)}} | 7.347 7{{esp | (0.012 3 Earths | Kilogram per cubic metre>kg/m³ | 1.622 Metre per second squared | }} {{nowrap>(0.165 4 g)}} | Metre per second>m/s | Day>d (synchronous) | | rot_velocity = 4.627 m/secliptic)
6.687° (to Orbital plane (astronomy)>orbit plane) | 10.1364/AO.47.004981 | YEAR=2008 | FIRST1=GRANT | VOLUME=47 | PMID=18806861, 27, |
[The maximum value is given based on scaling of the brightness from the value of −12.74 given for an equator to Moon-centre distance of 378 000 km in the NASA factsheet reference to the minimum Earth-Moon distance given there, after the latter is corrected for the Earth's equatorial radius of 6 378 km, giving 350 600 km. The minimum value (for a distant new Moon) is based on a similar scaling using the maximum Earth-Moon distance of 407 000 km (given in the factsheet) and by calculating the brightness of the earthshine onto such a new Moon. The brightness of the earthshine is {{nowrap>[ Earth albedo ×}} {{nowrap]| Earth radius /}} Radius of Orbit of the Moon>Moon's orbit)² ] relative to the direct solar illumination that occurs for a full Moon. ({{nowrap | Earth radius = (polar}} radius × equatorial {{nowrap|radius) | ½ = 6 367 km}}).
Minute of arc>arcminutes | [The range of angular size values given are based on simple scaling of the following values given in the fact sheet reference: at an Earth-equator to Moon-centre distance of 378 000 km, the angular size is 1896 arcseconds. The same fact sheet gives extreme Earth-Moon distances of 407 000 km and 357 000 km. For the maximum angular size, the minimum distance has to be corrected for the Earth's equatorial radius of 6 378 km, giving 350 600 km.]
[A.R. VASAVADA, D.A. PAIGE, AND S.E. WOOD ]| TITLE= NEAR-SURFACE TEMPERATURES ON MERCURY AND THE MOON AND THE STABILITY OF POLAR ICE DEPOSITS | PAGES=179 | URL=HTTP://ADSABS.HARVARD.EDU/ABS/1999ICAR..141..179V | YEAR= 1999, |
[Lucey et al. (2006) give 107 particles Cubic centimetre>cm−3 by day and 105 particles cm−3 by night. Along with equatorial surface temperatures of 390 Kelvin]| by day and 100 K by night, the ideal gas law yields the pressures given in the infobox (rounded to the nearest order of magnitude; 10−7 | Pascal (unit)>Pa by day and 10−10 Pa by night.
[More accurately, the Moon's mean sidereal period (fixed star to fixed star) is 27.321661 days (27d 07h 43m 11.5s), and its mean tropical orbital period (from equinox to equinox) is 27.321582 days (27d 07h 43m 04.7s) (Explanatory Supplement to the Astronomical Ephemeris, 1961, at p.107).]
[More accurately, the Moon's mean synodic period (between mean solar conjunctions) is 29.530589 days (29d 12h 44m 02.9s) (Explanatory Supplement to the Astronomical Ephemeris, 1961, at p.107).]
[WEB, Spudis, P.D., 2004,weblink Moon, World Book Online Reference Center, NASA, 2007-04-12, ]
[NEWS,weblink NASA Aims for Moon by 2018, Unveils New Ship, John, Roach, National Geographic, September 19, 2005, July 14, 2009, ]
[NEWS,weblink NASA to Unveil Plans to Send 4 Astronauts to Moon in 2018, Brian, Berger, Space.com, September 14, 2005, July 14, 2005, ]
[NEWS,weblink US plans to be back on the Moon by 2018, Catherine, Elsworth, September 20, 2005, July 14, 2009, ]
[WEB,weblink NASA finds 'significant' water on moon, CNN, November 13, 2009, ]
[WEB,weblink Naming Astronomical Objects, International Astronomical Union, January 10, 2008, ]
[WEB,weblink Gazetteer of Planetary Nomenclature: Planetary Nomenclature FAQ, USGS Astrogeology Research Program, November 16, 2008, ]
[BOOK, Dictionary of Greek and Roman Biography and Mythology: Oarses-Zygia, 3, William George Smith, J. Walton, 1849, 768,weblink 2010-03-06, ]
[BOOK, Thesaurus graecae linguae, 5, Henri Estienne, Didot, 1846, 1001,weblink 2010-03-06, ]
[WEB,weblink Harper, D., Moon, Online Etymology Dictionary, November, 2001, 2008-02-05, ]
[JOURNAL, Alexander, M. E., The Weak Friction Approximation and Tidal Evolution in Close Binary Systems, Astrophysics and Space Science, 1973, 23, 459–508,weblink 2007-04-12, 10.1007/BF00645172, ]
[WEB, Dark Side of the Moon, Phil Plait, Bad Astronomy:Misconceptions,weblink 2010-02-15, ]
[WEB, Luna 3, NASA,weblink 2010-02-15, ]
[WEB, Landscapes from the ancient and eroded lunar far side, esa,weblink 2010-02-15, ]
Maria
The dark and relatively featureless lunar plains which can clearly be seen with the naked eye are called maria (singular mare), Latin for seas, since they were believed by ancient astronomers to be filled with water. These are now known to be vast solidified pools of ancient basaltic lava. The majority of these lavas erupted or flowed into the depressions associated with impact basins that formed by the collisions of meteors and comets with the lunar surface. (Oceanus Procellarum is a major exception in that it does not correspond to a known impact basin.) Maria are found almost exclusively on the near side of the Moon, with the far side having only a few scattered patches covering about 2% of its surface,[JOURNAL, Gillis, J.J., Spudis, P.D., The Composition and Geologic Setting of Lunar Far Side Maria, Lunar and Planetary Science, 1996, 27, 413–404,weblink 2007-04-12, ]
[JOURNAL, Shearer, C., et al., Thermal and magmatic evolution of the Moon, Reviews in Mineralogy and Geochemistry, 60, 365–518, 2006, 10.2138/rmg.2006.60.4, ]
[WEB,weblink A New Moon for the Twenty-First Century, Taylor, G.J., Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2000-08-31, 2007-04-12, ]
[JOURNAL, Head, L.W.J.W., Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement, Journal of Geophysical Research, 2003, 108,weblink 2007-04-12, 10.1029/2002JE001909, 5012, ]
[WEB, W., Kiefer, 2000-10-03,weblink Lunar Orbiter: Impact Basin Geology, Lunar and Planetary Institute, 2007-04-12, ]
[WEB, Munsell, K., NASA, Solar System Exploration, Majestic Mountains,weblink 2006-12-04, 2007-04-12, ]
[WEB,weblink The Moon's Dark, Icy Poles, Martel, L.M.V., Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2003-06-04, 2007-04-12, ]
[BOOK, Impact cratering: A geologic process, Melosh, H. J., Oxford Univ. Press, 1989, 0195042840, ]
[WEB,weblink Nasa Spacecraft Reveal Largest Crater in Solar System - on Mars, 2008-06-26, ]
[WEB,weblink The Biggest Hole in the Solar System, Taylor, G.J., 1998-07-17, Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2007-04-12, ]
[BOOK, Heiken, G., Vaniman, D.; French, B. (eds.), 1991, Lunar Sourcebook, a user's guide to the Moon, Cambridge University Press, New York, 736, 0521334446, ]
[JOURNAL, Rasmussen, K.L., Warren, P.H., Megaregolith thickness, heat flow, and the bulk composition of the Moon, Nature, 1985, 313, 121–124,weblink 2007-04-12, 10.1038/313121a0, ]
[WEB, 2006-01-30, 2010-03-15,weblink The Smell of Moondust, NASA, ]
[WEB,weblink Lunar Polar Composites, Lunar and Planetary Institute, 2007-04-12, ]
[WEB,weblink Eureka! Ice found at lunar poles, Lunar Prospector (NASA), 2001-08-31, 2007-04-12, ]
[WEB, Spudis, P., Ice on the Moon,weblink The Space Review, 2006-11-06, 2007-04-12, ]
[WEB, Minkel, J.R., 9 July 2008, Moon Once Harbored Water, Lunar Lava Beads Show,weblink Scientific American]
[HTTP://WWW.SPIEGEL.DE/WISSENSCHAFT/WELTALL/0,1518,564911,00.HTML ] | PUBLISHER = SPIEGEL ONLINE | ACCESSDATE = 2010-03-15, |
[WEB,weblink The Times, September 24, 2009, India’s lunar mission finds evidence of water on the Moon, ]
[WEB,weblink Water Molecules Found on the Moon, Nasa, September 24, 2009, ]
[NEWS,weblink NASA: 'lots of water' on the moon, November 13, 2009, Toronto Star, 2009-11-13, ]
[Timing of crystallization of the lunar magma ocean constrained by the oldest zircon, Nemchin, Timms, Pidgeon, Geisler, Reddy & Meyer, published in Nature 25 January 2009, latest access 4 February 2009]
[JOURNAL, Lucey, P., et al., Understanding the lunar surface and space-Moon interactions, Reviews in Mineralogy and Geochemistry, 60, 83–219, 2006, 10.2138/rmg.2006.60.2, ]
[WEB,weblink Moon Composition and Resources (It's Not Made of Cheese!), Jean Hemzacek, Laukant, Northeastern Illinois University, 2004, 2009-08-29, ]
[JOURNAL,weblink Global Elemental Maps of the Moon: The Lunar Prospector Gamma-Ray Spectrometer, Lawrence, D. J. et al., Science (journal), Science, 281, 5382, 1484–1489, 10.1126/science.281.5382.1484, 1095-9203, HighWire Press, 1998-08-11, 2009-08-29, ]
[JOURNAL, Wieczorek, M., et al., The constitution and structure of the lunar interior, Reviews in Mineralogy and Geochemistry, 60, 221–364, 2006, 10.2138/rmg.2006.60.3, ]
[JOURNAL, Williams, J.G., Turyshev, S.G.; Boggs, D.H.; Ratcliff, J.T., Lunar laser ranging science: Gravitational physics and lunar interior and geodesy, Advances in Space Research, 2006, 37, 1, 6771,weblink 2007-04-12, 10.1016/j.asr.2005.05.013, ]
[WEB,weblink Lunar Prospector (NASA), Doppler Gravity Experiment Results, 2001-08-31, 2010-03-17, ]
[JOURNAL, Muller, P., Sjogren, W., Masons: lunar mass concentrations, Science, 161, 680–684, 1968, 10.1126/science.161.3842.680, 17801458, 3842, ]
[JOURNAL, Konopliv, A., Asmar, S.; Carranza, E.; Sjogren, W.; Yuan, D., Recent gravity models as a result of the Lunar Prospector mission, Icarus, 50, 1–18, 2001, 10.1006/icar.2000.6573, ]
[WEB,weblink Lunar Prospector (NASA), Magnetometer / Electron Reflectometer Results, 2001, 2010-03-17, ]
[JOURNAL, Hood, L.L., Huang, Z., Formation of magnetic anomalies antipodal to lunar impact basins: Two-dimensional model calculations, J. Geophys. Res., 96, 9837–9846, 1991, 10.1029/91JB00308, ]
[WEB, Globus, Ruth, Impact Upon Lunar Atmosphere,weblink 2002, 2010-03-17, ]
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[JOURNAL, Crotts, Arlin P.S., Lunar Outgassing, Transient Phenomena and The Return to The Moon, I: Existing Data., 2008, Department of Astronomy, Columbia University,weblink PDF, 2009-09-29, ]
[JOURNAL, Lawson, S., Feldman, W.; Lawrence, D.; Moore, K.; Elphic, R.; Belian, R., Recent outgassing from the lunar surface: the Lunar Prospector alpha particle spectrometer, J. Geophys. Res., 110, 1029, 2005, 10.1029/2005JE002433, ]
[JOURNAL, Stern, S.A., The Lunar atmosphere: History, status, current problems, and context, Rev. Geophys., 37, 1999, 453–491, 10.1029/1999RG900005, ]
[WEB, September 27, 2000, The Artemis Project, Marvin, Ostrega,weblink Lunar Surface Temperatures, 2010-03-17, ]
[JOURNAL, 10.1126/science.1118842, Science (journal), Science, 2005, 310, 5754, 1671–1674, Hf–W Chronometry of Lunar Metals and the Age and Early Differentiation of the Moon, Kleine, T., Palme, H.; Mezger, K.; Halliday, A.N., 16308422, ]
[JOURNAL, Binder, A.B., On the origin of the Moon by rotational fission, The Moon, 1974, 11, 2, 53–76,weblink 10.1007/BF01877794, ]
[BOOK, Stroud, Rick, The Book of the Moon, Walken and Company, 2009, 24–27, 0802717349, ]
[JOURNAL, Mitler, H.E., Formation of an iron-poor moon by partial capture, or: Yet another exotic theory of lunar origin, Icarus (journal), Icarus, 1975, 24, 256–268,weblink 10.1016/0019-1035(75)90102-5, ]
[JOURNAL, Stevenson, D.J., Origin of the moon–The collision hypothesis, Annual Review of Earth and Planetary Sciences, 1987, 15, 271–315,weblink 10.1146/annurev.ea.15.050187.001415, ]
[JOURNAL, Canup, R., Asphaug, E., Origin of the Moon in a giant impact near the end of the Earth's formation, Nature, 412, 708–712, 2001, 10.1038/35089010, 11507633, 6848, ]
[JOURNAL, Nield, Ted, Moonwalk (summary of meeting at Meteoritical Society's 72nd Annual Meeting, Nancy, France), Geoscientist, 19, 8, 2009,weblink ]
Geologic evolution
{{See also|Geology of the Moon}}A large portion of the Moon's post–magma-ocean geologic (or, more properly, "selenologic") evolution was dominated by impact cratering. The lunar geologic timescale is largely divided in time based on prominent basin-forming impact events, such as Nectaris, Imbrium, and Orientale. These impact structures are characterised by multiple rings of uplifted material, and are typically hundreds to thousands of kilometres in diameter. Each multi-ring basin is associated with a broad apron of ejecta deposits that forms a regional stratigraphic horizon. While only a few multi-ring basins have been definitively dated, they are useful for assigning relative ages on stratigraphic grounds. The continuous effects of impact cratering are responsible for forming the regolith.The other major geologic process that affected the Moon's surface was mare volcanism. The enhancement of heat-producing elements within the Procellarum KREEP Terrane is thought to have caused the underlying mantle to heat up, and eventually, to partially melt. A portion of these magmas rose to the surface and erupted, accounting for the high concentration of mare basalts on the near side of the Moon.[JOURNAL, Papike, J., Ryder, G.; Shearer, C., Lunar Samples, Reviews in Mineralogy and Geochemistry, 36, 5.1–5.234, 1998, ]
[JOURNAL, Hiesinger, H., Head, J.W.; Wolf, U.; Jaumanm, R.; Neukum, G., Ages and stratigraphy of mare basalts in Oceanus Procellarum, Mare Numbium, Mare Cognitum, and Mare Insularum, J. Geophys. Res., 108, 1029, 2003, 10.1029/2002JE001985, ]
[WEB,weblink Taylor, G.J., Recent Gas Escape from the Moon, Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2006-11-08, 2007-04-12, ]
[JOURNAL, Schultz, P.H., Staid, M.I.; Pieters, C.M., 2006, Lunar activity from recent gas release, Nature, 444, 184–186, 10.1038/nature05303, 17093445, 7116, ]
[WEB,weblink The Oldest Moon Rocks, Norman, M., Planetary Science Research Discoveries, 2004-04-21, 2007-04-12, ]
[BOOK, Varricchio, L., Inconstant Moon, Xlibris Books, 2006, 1-59926-393-9, ]
[WEB, Ray, R., 2001-05-15,weblink Ocean Tides and the Earth's Rotation, IERS Special Bureau for Tides, 2010-03-17, ]
[WEB,weblink Apollo Laser Ranging Experiments Yield Results, NASA, 2005-07-11, 2010-03-17, ]
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[WEB,weblink Vamplew, A., Cruithne: A little world linked to the Earth and no, it's not our second moon, 2010-03-17, ]
[JOURNAL, Morais, M.H.M., Morbidelli, A., The Population of Near-Earth Asteroids in Coorbital Motion with the Earth, Icarus, 2002, 160, 1–9,weblink 2010-03-17, 10.1006/icar.2002.6937, ]
[WEB, Phillips, Tony, Science@NASA, Stereo Eclipse, March 12, 2007, 2010-03-17,weblink ]
[WEB, F., Espenak, 2000,weblink Solar Eclipses for Beginners, MrEclipse, 2010-03-17, ]
[WEB, Thieman, J., Keating, S., 2006-05-02,weblink Eclipse 99, Frequently Asked Questions, NASA, 2007-04-12, ]
[WEB,weblink Espenak, F., Saros Cycle, NASA, 2010-03-17, ]
[WEB,weblink Total Lunar Occultations, Royal Astronomical Society of New Zealand, 2010-03-17, ]
[JOURNAL, The Square Degree as a Unit of Celestial Area, Guthrie, D.V., 1947, Popular Astronomy, 55, 200–203,weblink ]
[WEB, How Bright is the Moon?, Luciuk, Mike,weblink 2010-03-16, ]
[WEB,weblink Curious About Astronomy, Is the Moon seen as a crescent (and not a "boat") all over the world?, 2002-10-18, K., Spekkens, 2010-03-16, ]
missing image!
- Aldrin Apollo 11.jpg -
alt=An astronaut in an American Apollo-program spacesuit, standing on the flat, heavily footprinted landing area, with the utterly black sky of space above the horizon. His shadow is cast partly towards the photographer, and his reflective gold visor shows the similarly suited astronaut taking the photograph.|Astronaut Buzz Aldrin photographed by Neil Armstrong during the first Moon landing on July 20, 1969
The landing of the first humans on the Moon in 1969 is seen by many as the culmination of the space race.[NEWS, Coren, M, 'Giant leap' opens world of possibility, CNN.com, July 26, 2004,weblink 2010-03-16, ]
[PRESS RELEASE, NASA news release 77-47 page 242, September 1, 1977,weblink 2010-03-16, PDF, ]
[NEWS,weblink August 29, 2007, NASA Turns A Deaf Ear To The Moon, 1977, OASI Newsletters Archive, Appleton, James, Charles Radley, John Deans, Simon Harvey, Paul Burt, Michael Haxell, Roy Adams, N Spooner and Wayne Brieske, ]
[JOURNAL, Dickey, J., et al., 1994, Lunar laser ranging: a continuing legacy of the Apollo program, Science, 265, 482–490, 10.1126/science.265.5171.482, 17781305, 5171, ]
[PRESS RELEASE,weblink President Bush Offers New Vision For NASA, December 14, 2004, NASA, 2007-04-12, ]
[PRESS RELEASE, NASA Unveils Global Exploration Strategy and Lunar Architecture, NASA, December 4, 2006,weblink 2007-04-12, ]
[NEWS,weblink Japan Embarks on the Largest Moon Mission Since Apollo, Rita, O'Connor, October 1, 2007, 2009-07-14, ]
[WEB,weblink SPACE.com, India's Space Agency Proposes Manned Spaceflight Program, November 10, 2006, 2008-10-23, ]
[WEB,weblink Russia Plans Ambitious Robotic Lunar Mission, Covault, C., Aviation Week, June 4, 2006, 2007-04-12, ]
[WEB,weblink Carved and Drawn Prehistoric Maps of the Cosmos, Space Today Online, 2006, 2007-04-12, ]
[JOURNAL, Bartel Leendert, van der Waerden, Bartel Leendert van der Waerden, 1987, The Heliocentric System in Greek, Persian and Hindu Astronomy, Annals of the New York Academy of Sciences, 500, 1, 3296915, ]
[WEB, O'Connor, J.J., Robertson, E.F., February, 1999,weblink Anaxagoras of Clazomenae, University of St Andrews, 2007-04-12, ]
[BOOK, C. S., Lewis, C. S. Lewis, The Discarded Image, 108, Cambridge University Press, 1964, Cambridge, 0-521047735-2, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 411, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 413–414, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 227, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 415–416, 0-521058015, ]
[JOURNAL, The Book of Bodies and Distances of Habash al-Hasib, Langermann, Y. Tzvi, Centaurus (journal), Centaurus, 1985, 28, 108–128 [112], 10.1111/j.1600-0498.1985.tb00831.x, ]
[JOURNAL, The Book of Bodies and Distances of Habash al-Hasib, Langermann, Y. Tzvi, Centaurus (journal), Centaurus, 1985, 28, 108–128 [111], 10.1111/j.1600-0498.1985.tb00831.x, ]
[BOOK, The Moon illusion, Maurice, Hershenson, Routledge, 1989, 9780805801217, 9–10, ]
[JOURNAL, G. J., Toomer, Review: Ibn al-Haythams Weg zur Physik by Matthias Schramm, Isis, 55, 4, December 1964, 1964, 463–465, 10.1086/349914, ]
[WEB, Van Helden, A., 1995,weblink The Moon, Galileo Project, 2007-04-12, ]
[WEB,weblink The Great Moon Hoax, Boese, A., Museum of Hoaxes, 2002, 2007-04-12, ]
[WEB, International Space Law, United Nations Office for Outer Space Affairs,weblink 2006, 2007-04-12, ]
[WEB,weblink theregister.co.uk, NASA crushes lunar real estate industry, 2010-03-15, 2006-12-08, ]
References
-
1,737.10 km }} {{nowrap|(0.273 Earths)}} | 3.793{{esp | (0.074 Earths)}} | 2.195 8{{esp | 1 E+9 m³>km³ }} {{nowrap|(0.020 Earths)}} | 7.347 7{{esp | (0.012 3 Earths | Kilogram per cubic metre>kg/m³ | 1.622 Metre per second squared | }} {{nowrap>(0.165 4 g)}} | Metre per second>m/s | Day>d (synchronous) | | rot_velocity = 4.627 m/secliptic)
6.687° (to Orbital plane (astronomy)>orbit plane) | 10.1364/AO.47.004981 | YEAR=2008 | FIRST1=GRANT | VOLUME=47 | PMID=18806861, 27, |
[The maximum value is given based on scaling of the brightness from the value of −12.74 given for an equator to Moon-centre distance of 378 000 km in the NASA factsheet reference to the minimum Earth-Moon distance given there, after the latter is corrected for the Earth's equatorial radius of 6 378 km, giving 350 600 km. The minimum value (for a distant new Moon) is based on a similar scaling using the maximum Earth-Moon distance of 407 000 km (given in the factsheet) and by calculating the brightness of the earthshine onto such a new Moon. The brightness of the earthshine is {{nowrap>[ Earth albedo ×}} {{nowrap]| Earth radius /}} Radius of Orbit of the Moon>Moon's orbit)² ] relative to the direct solar illumination that occurs for a full Moon. ({{nowrap | Earth radius = (polar}} radius × equatorial {{nowrap|radius) | ½ = 6 367 km}}).
Minute of arc>arcminutes | [The range of angular size values given are based on simple scaling of the following values given in the fact sheet reference: at an Earth-equator to Moon-centre distance of 378 000 km, the angular size is 1896 arcseconds. The same fact sheet gives extreme Earth-Moon distances of 407 000 km and 357 000 km. For the maximum angular size, the minimum distance has to be corrected for the Earth's equatorial radius of 6 378 km, giving 350 600 km.]
[A.R. VASAVADA, D.A. PAIGE, AND S.E. WOOD ]| TITLE= NEAR-SURFACE TEMPERATURES ON MERCURY AND THE MOON AND THE STABILITY OF POLAR ICE DEPOSITS | PAGES=179 | URL=HTTP://ADSABS.HARVARD.EDU/ABS/1999ICAR..141..179V | YEAR= 1999, |
[Lucey et al. (2006) give 107 particles Cubic centimetre>cm−3 by day and 105 particles cm−3 by night. Along with equatorial surface temperatures of 390 Kelvin]| by day and 100 K by night, the ideal gas law yields the pressures given in the infobox (rounded to the nearest order of magnitude; 10−7 | Pascal (unit)>Pa by day and 10−10 Pa by night.
[More accurately, the Moon's mean sidereal period (fixed star to fixed star) is 27.321661 days (27d 07h 43m 11.5s), and its mean tropical orbital period (from equinox to equinox) is 27.321582 days (27d 07h 43m 04.7s) (Explanatory Supplement to the Astronomical Ephemeris, 1961, at p.107).]
[More accurately, the Moon's mean synodic period (between mean solar conjunctions) is 29.530589 days (29d 12h 44m 02.9s) (Explanatory Supplement to the Astronomical Ephemeris, 1961, at p.107).]
[WEB, Spudis, P.D., 2004,weblink Moon, World Book Online Reference Center, NASA, 2007-04-12, ]
[NEWS,weblink NASA Aims for Moon by 2018, Unveils New Ship, John, Roach, National Geographic, September 19, 2005, July 14, 2009, ]
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[NEWS,weblink US plans to be back on the Moon by 2018, Catherine, Elsworth, September 20, 2005, July 14, 2009, ]
[WEB,weblink NASA finds 'significant' water on moon, CNN, November 13, 2009, ]
[WEB,weblink Naming Astronomical Objects, International Astronomical Union, January 10, 2008, ]
[WEB,weblink Gazetteer of Planetary Nomenclature: Planetary Nomenclature FAQ, USGS Astrogeology Research Program, November 16, 2008, ]
[BOOK, Dictionary of Greek and Roman Biography and Mythology: Oarses-Zygia, 3, William George Smith, J. Walton, 1849, 768,weblink 2010-03-06, ]
[BOOK, Thesaurus graecae linguae, 5, Henri Estienne, Didot, 1846, 1001,weblink 2010-03-06, ]
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[JOURNAL, Alexander, M. E., The Weak Friction Approximation and Tidal Evolution in Close Binary Systems, Astrophysics and Space Science, 1973, 23, 459–508,weblink 2007-04-12, 10.1007/BF00645172, ]
[WEB, Dark Side of the Moon, Phil Plait, Bad Astronomy:Misconceptions,weblink 2010-02-15, ]
[WEB, Luna 3, NASA,weblink 2010-02-15, ]
[WEB, Landscapes from the ancient and eroded lunar far side, esa,weblink 2010-02-15, ]
Maria
The dark and relatively featureless lunar plains which can clearly be seen with the naked eye are called maria (singular mare), Latin for seas, since they were believed by ancient astronomers to be filled with water. These are now known to be vast solidified pools of ancient basaltic lava. The majority of these lavas erupted or flowed into the depressions associated with impact basins that formed by the collisions of meteors and comets with the lunar surface. (Oceanus Procellarum is a major exception in that it does not correspond to a known impact basin.) Maria are found almost exclusively on the near side of the Moon, with the far side having only a few scattered patches covering about 2% of its surface,[JOURNAL, Gillis, J.J., Spudis, P.D., The Composition and Geologic Setting of Lunar Far Side Maria, Lunar and Planetary Science, 1996, 27, 413–404,weblink 2007-04-12, ]
[JOURNAL, Shearer, C., et al., Thermal and magmatic evolution of the Moon, Reviews in Mineralogy and Geochemistry, 60, 365–518, 2006, 10.2138/rmg.2006.60.4, ]
[WEB,weblink A New Moon for the Twenty-First Century, Taylor, G.J., Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2000-08-31, 2007-04-12, ]
[JOURNAL, Head, L.W.J.W., Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement, Journal of Geophysical Research, 2003, 108,weblink 2007-04-12, 10.1029/2002JE001909, 5012, ]
[WEB, W., Kiefer, 2000-10-03,weblink Lunar Orbiter: Impact Basin Geology, Lunar and Planetary Institute, 2007-04-12, ]
[WEB, Munsell, K., NASA, Solar System Exploration, Majestic Mountains,weblink 2006-12-04, 2007-04-12, ]
[WEB,weblink The Moon's Dark, Icy Poles, Martel, L.M.V., Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2003-06-04, 2007-04-12, ]
[BOOK, Impact cratering: A geologic process, Melosh, H. J., Oxford Univ. Press, 1989, 0195042840, ]
[WEB,weblink Nasa Spacecraft Reveal Largest Crater in Solar System - on Mars, 2008-06-26, ]
[WEB,weblink The Biggest Hole in the Solar System, Taylor, G.J., 1998-07-17, Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2007-04-12, ]
[BOOK, Heiken, G., Vaniman, D.; French, B. (eds.), 1991, Lunar Sourcebook, a user's guide to the Moon, Cambridge University Press, New York, 736, 0521334446, ]
[JOURNAL, Rasmussen, K.L., Warren, P.H., Megaregolith thickness, heat flow, and the bulk composition of the Moon, Nature, 1985, 313, 121–124,weblink 2007-04-12, 10.1038/313121a0, ]
[WEB, 2006-01-30, 2010-03-15,weblink The Smell of Moondust, NASA, ]
[WEB,weblink Lunar Polar Composites, Lunar and Planetary Institute, 2007-04-12, ]
[WEB,weblink Eureka! Ice found at lunar poles, Lunar Prospector (NASA), 2001-08-31, 2007-04-12, ]
[WEB, Spudis, P., Ice on the Moon,weblink The Space Review, 2006-11-06, 2007-04-12, ]
[WEB, Minkel, J.R., 9 July 2008, Moon Once Harbored Water, Lunar Lava Beads Show,weblink Scientific American]
[HTTP://WWW.SPIEGEL.DE/WISSENSCHAFT/WELTALL/0,1518,564911,00.HTML ] | PUBLISHER = SPIEGEL ONLINE | ACCESSDATE = 2010-03-15, |
[WEB,weblink The Times, September 24, 2009, India’s lunar mission finds evidence of water on the Moon, ]
[WEB,weblink Water Molecules Found on the Moon, Nasa, September 24, 2009, ]
[NEWS,weblink NASA: 'lots of water' on the moon, November 13, 2009, Toronto Star, 2009-11-13, ]
[Timing of crystallization of the lunar magma ocean constrained by the oldest zircon, Nemchin, Timms, Pidgeon, Geisler, Reddy & Meyer, published in Nature 25 January 2009, latest access 4 February 2009]
[JOURNAL, Lucey, P., et al., Understanding the lunar surface and space-Moon interactions, Reviews in Mineralogy and Geochemistry, 60, 83–219, 2006, 10.2138/rmg.2006.60.2, ]
[WEB,weblink Moon Composition and Resources (It's Not Made of Cheese!), Jean Hemzacek, Laukant, Northeastern Illinois University, 2004, 2009-08-29, ]
[JOURNAL,weblink Global Elemental Maps of the Moon: The Lunar Prospector Gamma-Ray Spectrometer, Lawrence, D. J. et al., Science (journal), Science, 281, 5382, 1484–1489, 10.1126/science.281.5382.1484, 1095-9203, HighWire Press, 1998-08-11, 2009-08-29, ]
[JOURNAL, Wieczorek, M., et al., The constitution and structure of the lunar interior, Reviews in Mineralogy and Geochemistry, 60, 221–364, 2006, 10.2138/rmg.2006.60.3, ]
[JOURNAL, Williams, J.G., Turyshev, S.G.; Boggs, D.H.; Ratcliff, J.T., Lunar laser ranging science: Gravitational physics and lunar interior and geodesy, Advances in Space Research, 2006, 37, 1, 6771,weblink 2007-04-12, 10.1016/j.asr.2005.05.013, ]
[WEB,weblink Lunar Prospector (NASA), Doppler Gravity Experiment Results, 2001-08-31, 2010-03-17, ]
[JOURNAL, Muller, P., Sjogren, W., Masons: lunar mass concentrations, Science, 161, 680–684, 1968, 10.1126/science.161.3842.680, 17801458, 3842, ]
[JOURNAL, Konopliv, A., Asmar, S.; Carranza, E.; Sjogren, W.; Yuan, D., Recent gravity models as a result of the Lunar Prospector mission, Icarus, 50, 1–18, 2001, 10.1006/icar.2000.6573, ]
[WEB,weblink Lunar Prospector (NASA), Magnetometer / Electron Reflectometer Results, 2001, 2010-03-17, ]
[JOURNAL, Hood, L.L., Huang, Z., Formation of magnetic anomalies antipodal to lunar impact basins: Two-dimensional model calculations, J. Geophys. Res., 96, 9837–9846, 1991, 10.1029/91JB00308, ]
[WEB, Globus, Ruth, Impact Upon Lunar Atmosphere,weblink 2002, 2010-03-17, ]
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[JOURNAL, Crotts, Arlin P.S., Lunar Outgassing, Transient Phenomena and The Return to The Moon, I: Existing Data., 2008, Department of Astronomy, Columbia University,weblink PDF, 2009-09-29, ]
[JOURNAL, Lawson, S., Feldman, W.; Lawrence, D.; Moore, K.; Elphic, R.; Belian, R., Recent outgassing from the lunar surface: the Lunar Prospector alpha particle spectrometer, J. Geophys. Res., 110, 1029, 2005, 10.1029/2005JE002433, ]
[JOURNAL, Stern, S.A., The Lunar atmosphere: History, status, current problems, and context, Rev. Geophys., 37, 1999, 453–491, 10.1029/1999RG900005, ]
[WEB, September 27, 2000, The Artemis Project, Marvin, Ostrega,weblink Lunar Surface Temperatures, 2010-03-17, ]
[JOURNAL, 10.1126/science.1118842, Science (journal), Science, 2005, 310, 5754, 1671–1674, Hf–W Chronometry of Lunar Metals and the Age and Early Differentiation of the Moon, Kleine, T., Palme, H.; Mezger, K.; Halliday, A.N., 16308422, ]
[JOURNAL, Binder, A.B., On the origin of the Moon by rotational fission, The Moon, 1974, 11, 2, 53–76,weblink 10.1007/BF01877794, ]
[BOOK, Stroud, Rick, The Book of the Moon, Walken and Company, 2009, 24–27, 0802717349, ]
[JOURNAL, Mitler, H.E., Formation of an iron-poor moon by partial capture, or: Yet another exotic theory of lunar origin, Icarus (journal), Icarus, 1975, 24, 256–268,weblink 10.1016/0019-1035(75)90102-5, ]
[JOURNAL, Stevenson, D.J., Origin of the moon–The collision hypothesis, Annual Review of Earth and Planetary Sciences, 1987, 15, 271–315,weblink 10.1146/annurev.ea.15.050187.001415, ]
[JOURNAL, Canup, R., Asphaug, E., Origin of the Moon in a giant impact near the end of the Earth's formation, Nature, 412, 708–712, 2001, 10.1038/35089010, 11507633, 6848, ]
[JOURNAL, Nield, Ted, Moonwalk (summary of meeting at Meteoritical Society's 72nd Annual Meeting, Nancy, France), Geoscientist, 19, 8, 2009,weblink ]
Geologic evolution
{{See also|Geology of the Moon}}A large portion of the Moon's post–magma-ocean geologic (or, more properly, "selenologic") evolution was dominated by impact cratering. The lunar geologic timescale is largely divided in time based on prominent basin-forming impact events, such as Nectaris, Imbrium, and Orientale. These impact structures are characterised by multiple rings of uplifted material, and are typically hundreds to thousands of kilometres in diameter. Each multi-ring basin is associated with a broad apron of ejecta deposits that forms a regional stratigraphic horizon. While only a few multi-ring basins have been definitively dated, they are useful for assigning relative ages on stratigraphic grounds. The continuous effects of impact cratering are responsible for forming the regolith.The other major geologic process that affected the Moon's surface was mare volcanism. The enhancement of heat-producing elements within the Procellarum KREEP Terrane is thought to have caused the underlying mantle to heat up, and eventually, to partially melt. A portion of these magmas rose to the surface and erupted, accounting for the high concentration of mare basalts on the near side of the Moon.[JOURNAL, Papike, J., Ryder, G.; Shearer, C., Lunar Samples, Reviews in Mineralogy and Geochemistry, 36, 5.1–5.234, 1998, ]
[JOURNAL, Hiesinger, H., Head, J.W.; Wolf, U.; Jaumanm, R.; Neukum, G., Ages and stratigraphy of mare basalts in Oceanus Procellarum, Mare Numbium, Mare Cognitum, and Mare Insularum, J. Geophys. Res., 108, 1029, 2003, 10.1029/2002JE001985, ]
[WEB,weblink Taylor, G.J., Recent Gas Escape from the Moon, Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology, 2006-11-08, 2007-04-12, ]
[JOURNAL, Schultz, P.H., Staid, M.I.; Pieters, C.M., 2006, Lunar activity from recent gas release, Nature, 444, 184–186, 10.1038/nature05303, 17093445, 7116, ]
[WEB,weblink The Oldest Moon Rocks, Norman, M., Planetary Science Research Discoveries, 2004-04-21, 2007-04-12, ]
[BOOK, Varricchio, L., Inconstant Moon, Xlibris Books, 2006, 1-59926-393-9, ]
[WEB, Ray, R., 2001-05-15,weblink Ocean Tides and the Earth's Rotation, IERS Special Bureau for Tides, 2010-03-17, ]
[WEB,weblink Apollo Laser Ranging Experiments Yield Results, NASA, 2005-07-11, 2010-03-17, ]
[JOURNAL]
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[WEB,weblink Vamplew, A., Cruithne: A little world linked to the Earth and no, it's not our second moon, 2010-03-17, ]
[JOURNAL, Morais, M.H.M., Morbidelli, A., The Population of Near-Earth Asteroids in Coorbital Motion with the Earth, Icarus, 2002, 160, 1–9,weblink 2010-03-17, 10.1006/icar.2002.6937, ]
[WEB, Phillips, Tony, Science@NASA, Stereo Eclipse, March 12, 2007, 2010-03-17,weblink ]
[WEB, F., Espenak, 2000,weblink Solar Eclipses for Beginners, MrEclipse, 2010-03-17, ]
[WEB, Thieman, J., Keating, S., 2006-05-02,weblink Eclipse 99, Frequently Asked Questions, NASA, 2007-04-12, ]
[WEB,weblink Espenak, F., Saros Cycle, NASA, 2010-03-17, ]
[WEB,weblink Total Lunar Occultations, Royal Astronomical Society of New Zealand, 2010-03-17, ]
[JOURNAL, The Square Degree as a Unit of Celestial Area, Guthrie, D.V., 1947, Popular Astronomy, 55, 200–203,weblink ]
[WEB, How Bright is the Moon?, Luciuk, Mike,weblink 2010-03-16, ]
[WEB,weblink Curious About Astronomy, Is the Moon seen as a crescent (and not a "boat") all over the world?, 2002-10-18, K., Spekkens, 2010-03-16, ]
missing image!
- Aldrin Apollo 11.jpg -
alt=An astronaut in an American Apollo-program spacesuit, standing on the flat, heavily footprinted landing area, with the utterly black sky of space above the horizon. His shadow is cast partly towards the photographer, and his reflective gold visor shows the similarly suited astronaut taking the photograph.|Astronaut Buzz Aldrin photographed by Neil Armstrong during the first Moon landing on July 20, 1969
The landing of the first humans on the Moon in 1969 is seen by many as the culmination of the space race.[NEWS, Coren, M, 'Giant leap' opens world of possibility, CNN.com, July 26, 2004,weblink 2010-03-16, ]
[PRESS RELEASE, NASA news release 77-47 page 242, September 1, 1977,weblink 2010-03-16, PDF, ]
[NEWS,weblink August 29, 2007, NASA Turns A Deaf Ear To The Moon, 1977, OASI Newsletters Archive, Appleton, James, Charles Radley, John Deans, Simon Harvey, Paul Burt, Michael Haxell, Roy Adams, N Spooner and Wayne Brieske, ]
[JOURNAL, Dickey, J., et al., 1994, Lunar laser ranging: a continuing legacy of the Apollo program, Science, 265, 482–490, 10.1126/science.265.5171.482, 17781305, 5171, ]
[PRESS RELEASE,weblink President Bush Offers New Vision For NASA, December 14, 2004, NASA, 2007-04-12, ]
[PRESS RELEASE, NASA Unveils Global Exploration Strategy and Lunar Architecture, NASA, December 4, 2006,weblink 2007-04-12, ]
[NEWS,weblink Japan Embarks on the Largest Moon Mission Since Apollo, Rita, O'Connor, October 1, 2007, 2009-07-14, ]
[WEB,weblink SPACE.com, India's Space Agency Proposes Manned Spaceflight Program, November 10, 2006, 2008-10-23, ]
[WEB,weblink Russia Plans Ambitious Robotic Lunar Mission, Covault, C., Aviation Week, June 4, 2006, 2007-04-12, ]
[WEB,weblink Carved and Drawn Prehistoric Maps of the Cosmos, Space Today Online, 2006, 2007-04-12, ]
[JOURNAL, Bartel Leendert, van der Waerden, Bartel Leendert van der Waerden, 1987, The Heliocentric System in Greek, Persian and Hindu Astronomy, Annals of the New York Academy of Sciences, 500, 1, 3296915, ]
[WEB, O'Connor, J.J., Robertson, E.F., February, 1999,weblink Anaxagoras of Clazomenae, University of St Andrews, 2007-04-12, ]
[BOOK, C. S., Lewis, C. S. Lewis, The Discarded Image, 108, Cambridge University Press, 1964, Cambridge, 0-521047735-2, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 411, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 413–414, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 227, 0-521058015, ]
[BOOK, Needham, Joseph, 1986, Science and Civilization in China, 3, Mathematics and the Sciences of the Heavens and Earth, Taipei, Caves Books, 415–416, 0-521058015, ]
[JOURNAL, The Book of Bodies and Distances of Habash al-Hasib, Langermann, Y. Tzvi, Centaurus (journal), Centaurus, 1985, 28, 108–128 [112], 10.1111/j.1600-0498.1985.tb00831.x, ]
[JOURNAL, The Book of Bodies and Distances of Habash al-Hasib, Langermann, Y. Tzvi, Centaurus (journal), Centaurus, 1985, 28, 108–128 [111], 10.1111/j.1600-0498.1985.tb00831.x, ]
[BOOK, The Moon illusion, Maurice, Hershenson, Routledge, 1989, 9780805801217, 9–10, ]
[JOURNAL, G. J., Toomer, Review: Ibn al-Haythams Weg zur Physik by Matthias Schramm, Isis, 55, 4, December 1964, 1964, 463–465, 10.1086/349914, ]
[WEB, Van Helden, A., 1995,weblink The Moon, Galileo Project, 2007-04-12, ]
[WEB,weblink The Great Moon Hoax, Boese, A., Museum of Hoaxes, 2002, 2007-04-12, ]
[WEB, International Space Law, United Nations Office for Outer Space Affairs,weblink 2006, 2007-04-12, ]
[WEB,weblink theregister.co.uk, NASA crushes lunar real estate industry, 2010-03-15, 2006-12-08, ]
Footnotes
- BOOK, The Clementine Atlas of the Moon, Bussey, B., Paul Spudis, Spudis, P.D., Cambridge University Press, 2004, 0-521-81528-2,
- JOURNAL, Jolliff, B., Wieczorek, M.; Shearer, C.; Neal, C. (eds.), New views of the Moon, Rev. Mineral. Geochem., Min. Soc. Amer., Chantilly, Virginia, 721, 2006, 60,weblink 2007-04-12, 10.2138/rmg.2006.60.0, 0939950723,
- BOOK, The Big Splat, or How Our Moon Came to Be, Mackenzie, Dana, John Wiley & Sons, Inc, Hoboken, New Jersey, 2003, 0471150576,
- BOOK, On the Moon, Patrick Moore, Moore, P., Sterling Publishing Co., Tucson, Arizona, 2001, 0-304-35469-4,
- BOOK, The Once and Future Moon, Spudis, P.D., Smithsonian Institution Press, 1996, 1-56098-634-4,
- BOOK, Taylor, S.R., Solar system evolution, Cambridge Univ. Press, 307, 1992, 0521372127,
- JOURNAL, Wilhelms, D.E., Geologic History of the Moon, U.S. Geological Survey Professional paper, 1987, 1348,weblink 2007-04-12,
- BOOK, To a Rocky Moon: A Geologist's History of Lunar Exploration, Wilhelms, D.E., University of Arizona Press, Tucson, Arizona, 1993,weblink 2009-03-10, 0816510652,
External links
- Images and maps
- WEB, Clementine Lunar Image Browser 1.5, U.S. Navy, 2003-10-15,weblink 2007-04-12,
- WEB, Digital Lunar Orbiter Photographic Atlas of the Moon, Lunar and Planetary Institute,weblink 2007-04-12,
- WEB, Google Moon, Google, 2007,weblink 2007-04-12,
- WEB, Lunar Atlases, Lunar and Planetary Institute,weblink 2007-04-12,
- WEB, Aeschliman, R, Lunar Maps, Planetary Cartography and Graphics,weblink 2007-04-12,
- WEB, Lunar Photo of the Day, 2004,weblink 2009-04-05,
- WEB, Moon, World Wind Central, NASA, 2007,weblink 2007-04-12,
- WEB, The Moon: 50 fantastic features, Skymania, 2007,weblink 2007-09-29,
- Video of Earth rising from moon orbit by the camera of the JAXA (Japanese) satellite Kaguya (Selene). See press release (The Earth only appears to rise because of the orbiting satellite. As seen from a stationary point on the Moon's surface the Earth doesn't move, because the Moon always shows the same side to the Earth.)
- Japan Aerospace Exploration Agency (JAXA), numerous Selene satellite Moon images beginning in 2007.
- Exploration
- WEB, Jones, E.M., Apollo Lunar Surface Journal, NASA, 2006,weblink 2007-04-12,
- WEB, Exploring the Moon, Lunar and Planetary Institute,weblink 2007-04-12,
- WEB, Teague, K., The Project Apollo Archive, 2006,weblink 2007-04-12,
- Moon phases
- WEB, Current Moon Phase, 2007,weblink 2007-04-12,
- WEB, NASA's SKYCAL—Sky Events Calendar, NASA Eclipse Home Page,weblink 2007-08-27,
- WEB, Virtual Reality Moon Phase Pictures, U.S. Naval Observatory,weblink 2007-04-12,
- WEB, Find moonrise, moonset and moonphase for a location, 2008,
weblink 2008-02-18,
- Others
- WEB, The Earth, Sun and Moon, Thinkquest.org,weblink 2008-07-17,
- WEB, Precession of Moon's orbit, 2004, Pearson Education Inc /Addison Wesley put on line by University of Hawaii Institute of Astronomy,weblink 2008-07-17,
- WEB, All About the Moon, Space.com, 2007,weblink 2007-04-12,
- Earth's Moon Profile by NASA's Solar System Exploration
- WEB, Moon Articles, in Planetary Science Research Discoveries, educational journal,weblink
- WEB, Williams, D.R., Moon Fact Sheet, NASA, 2006,weblink 2007-04-12,
- WEB, Moon Wiki, 2007,weblink 2007-09-06,
- WEB, Cain, Fraser, Where does the Moon Come From?, Universe Today,weblink 2008-04-01,
- Cartographic resources
- Movies
- Movie of the Moon's rotation at National Oceanic and Atmospheric Administration site
{{The Moon}}{{Solar System moons (compact)}}{{Solar System}}
MaanقمرPhaxsiAyচাঁদ(zh-min-nan:Go̍eh-niû)
Месяц, спадарожнік Зямлі(be-x-old:Месяц (спадарожнік Зямлі))
Mjesec (satelit)LlunaMěsícLunaLleuadMånenMondKuuΣελήνηLunaLunoIlargiaماهMáninLuneMoanne (himellichem)An GhealachYn EaystGealachLúaચંદ્ર달Լուսինचन्द्रमाMjesecBulanLunaᑕᖅᑭᖅ/taqqiqTungliðLunaהירחRembulanQaammatಚಂದ್ರმთვარეАй (серік)Mwezi (gimba la angani)ດວງຈັນLuna (satelles)MēnessMėnulisHoldМесечинаVolanaചന്ദ്രന്चंद्रBulan (satelit)СарMētztliMaan(nds-nl:Maone (eerde))
चन्द्रमा月MånenLunaOy (tabiiy yoʻldosh)ਚੰਦਰਮਾMaand (Eer)KsiężycLuaLunaGlinaKillaЛунаHënaචන්ද්රයාMoonMesiacLunaМесецMjesecBulan (satelit)KuuMånenBuwan (astronomiya)நிலாАй (юлдаш)చంద్రుడుดวงจันทร์МоҳAy (uydu)ƆbosomeМісяць (супутник)چاندRonghndwenMặt TrăngMun(fiu-vro:Kuu)(zh-classical:月)
לבנהÒsùpá(zh-yue:月光)(bat-smg:Mienolis)
月球
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- "moon" does not exist on GetWiki
- time: 5:55am EDT - Thu, Mar 18 2010
