The Moon is an astronomical body that orbits the planet Earth and is the only permanent natural satellite of Earth. It is the fifth largest natural satellite in the Solar System, and the largest among planetary satellites relative to the orbiting planetary size (primer). The moon was after the second most populous satellite of Jupiter Io satellite in the Solar System among those whose density was known.
The moon is estimated to form about 4.51 billion years ago, not long after Earth. The most widely accepted explanation is that the Moon is formed from the remaining debris after the giant impact between Earth and Mars-sized bodies called Theia.
The moon is in synchronous rotation with the Earth, and thus always shows the same side to the earth, the near side. The near side is characterized by a dark volcanic maria that fills the space between the ancient high plateau crust and the prominent impact crater. After the Sun, the Moon is the second most visible celestial body in the earth's sky. Its surface is really dark, though compared to the night sky it looks very bright, with only slightly higher reflectivity than worn asphalt. Its gravitational influence produces sea tides, the waves of the body, and a slight elongation of the day.
The average orbital distance of the Moon is 384,402 km (238,856 mi), or 1.28 seconds. It's about thirty times the diameter of the Earth. The clear size of the Moon in the sky is almost the same as the Sun (as it is 400x further and larger). Therefore, the Moon covering the Sun is almost right during the total solar eclipse. This apparent visual size matching will not continue in the future, as the Moon's distance from Earth slowly increases.
The moon was first achieved in 1959 by an unmanned spacecraft from the Luna program of the Soviet Union; The US NASA Apollo program has achieved the only manned lunar mission to date, beginning with the first manned orbital mission by Apollo 8 in 1968, and six manned landings between 1969 and 1972, with the first being Apollo 11. Missions this restores the moon rocks that have been used to develop the geological understanding of the Moon's origin, internal structure, and the history of the Moon. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.
The natural protrusion of the Moon in the sky of the world and its regular phase cycles as seen from Earth have provided references and cultural influences to human societies and cultures from time immemorial. Such cultural influences can be found in language, calendar system by month, art, and mythology.
Video Moon
Nama dan etimologi
The English name commonly used for Earth's natural satellites is "Moon", which in non-scientific texts is usually not capitalized. The noun month is from Old English m? Na , which (like all of the same Germanic languages) comes from Proto-Germanic * m? NÃÆ'Â' , originating from Proto-Indo-Europe * m? h? n? s "month", "moon", derived from Proto-Indo-European root * meh? - "to measure", the moon becomes the ancient unit of time measured by the Moon. Sometimes, the name "Luna" is used. In literature, especially science fiction, "Luna" is used to distinguish it from another month, while in poetry, the name has been used to denote the personification of our moon.
The modern English adjective associated with the Moon is lunar , derived from the Latin word for the Moon, luna . The selenic adjective (usually used to refer to selenium only) is very rarely used to refer to the Moon that this meaning is not recorded in most of the major dictionaries. It comes from the Ancient Greek word for the Moon, ?????? (cell? n?), from which however, the "seleno-" prefix, as in selenografi , the study of the Moon's physical features, as well as the name of the element selenium . Both the Greek goddess Selene and the Roman goddess Diana are alternatively called Cynthia. The names of Luna, Cynthia, and Selene are reflected in the terminology for the moon's orbit in words like apolune , pericynthion , and selenocentric . The name Diana comes from Proto-Indo-European * diw-yo , "heavenly", derived from PIE * dyeu- "root to shine," which in many derivatives means "heaven, heaven, and god "and is also the origin of the Latin dead ," day ".
Maps Moon
Formation
The moon formed 4.51 billion years ago, some 60 million years after the origin of the Solar System. Several forming mechanisms have been proposed, including the Moon's splitting of the Earth's crust through centrifugal force (which will require too much of the Earth's initial spin), the gravitational capture of the already formed Moon (which will require an unfairly extended atmosphere from Earth to dissipate the energy of the moon through), and the joint formation of Earth and Moon together in a primordial accretion disk (which does not explain the metal thinning in the Moon). This hypothesis also can not explain the high angular momentum of the Earth-Moon system.
The prevailing hypothesis is that the Earth-Moon system was formed after the impact of Mars-sized bodies (named Theia ) with proto-Earth. The impact is to bump the material into Earth's orbit and then the material increases and forms the Moon.
The far side of the Moon has a crust that is 30 miles (48 km) thicker than the near side. This is considered because the Moon is fused from two different bodies.
This hypothesis, though not perfect, probably best describes the evidence. Eighteen months prior to the October 1984 conference on the origin of the moon, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged lunar scientists: "You have eighteen months.Return to your Apollo data, go back to your computer, do whatever you want must do, but make up your mind Do not come to our conference unless you have something to say about the birth of the Moon. "At the 1984 conference in Kona, Hawaii, the giant impact hypothesis emerged as the most popular.
Before the conference, there were partisans from the three "traditional" theories, plus some people who started taking the giant's impact seriously, and there was a very apathetic who did not think the debate would be resolved. After that, there are basically only two groups: giant and agnostic camps.
The impact of the giant is considered to have been common in the early solar system. Computer simulations of the impact of giants have produced results consistent with the moon's core mass and the momentum of the Earth-Moon system's angle. This simulation also shows that most of the Moon comes from the crash, not the proto-Earth. However, newer simulations suggest a larger fraction of the Moon that comes from proto-Earth. Other bodies of the inner Solar System such as Mars and Vesta have, according to their meteorites, the composition of oxygen and tungsten isotopes very different from Earth. However, Earth and the Moon have almost identical isotope compositions. The isotope equation of the Earth-Moon system may be explained by the post-impact mixing of the volatile material that forms both, although this is disputed.
The impact releases a lot of energy and then the material is released back into Earth-Moon systems. It will melt the Earth's outermost shell, and thus form the ocean of magma. Similarly, the newly formed Moon will also be affected and has its own magma lunar ocean; its depth is estimated from about 500 km (300 miles) to 1,737 km (1,079 miles).
While the giant impact hypothesis may explain a lot of evidence, some questions are still unresolved, mostly involving the composition of the Moon.
In 2001, a team at the Carnegie Institute of Washington reported the most precise measurements of the isotopic signs of lunar rock. To their surprise, the stones of the Apollo program have the same isotope marks as the rocks from Earth, yet they are different from almost any other body in the Solar System. Indeed, this observation is unexpected, since most of the material that makes up the Moon is thought to have originated from Theia and was announced in 2007 that there is less than 1% chance that Theia and Earth have identical isotope marks. The other Apollo lunar lunar samples in 2012 have the same titanium isotope composition as the Earth, which contradicts what is expected if the Moon is distant from Earth or derived from Theia. This difference can be explained by the variation of the giant impact hypothesis.
Physical Characteristics
Internal structure
The moon is a different body: it has shells, mantle, and clear geochemical nucleus. The moon has a strong core of iron-rich nuclei with a radius as small as 240 km (150 mi) and the liquid outer core is mainly made of molten iron with a radius of about 300 km (190 mi). Around the core is a partially liquid boundary layer with a radius of about 500 km (310 mi). This structure is thought to have evolved through the crystallization of fractions from the global oceanic oceans shortly after the formation of the Moon 4.5 billion years ago. Crystallization of this ocean of magma will create mafic coats from deposition and drowning of olivine minerals, clinopiroksen, and orthopyroxes; after about three quarters of the ocean of magma has crystallized, lower-density plagioclase minerals may form and float into the crust above. The final liquid for crystallization will initially be flanked between the crust and the mantle, with a high abundance of unsuitable and heat-generating elements. Consistent with this perspective, geochemical mapping made from orbit shows the crust of most anorthosites. Moon rock samples from flood lava that erupt to the surface from partial melting in the mantle confirm the composition of mafic coats, which are richer in iron than Earth. The crust averages about 50 km (31 miles) thick.
The moon is the second most populous satellite in the Solar System, after Io. However, the core of the Moon is small, with a radius of about 350 km (220 mi) or less, about 20% of the Moon's radius. The composition is not well-defined, but it may be mixed with a small amount of sulfur and nickel; the time-variable rotation analysis of the Moon indicates that it is at least partially liquid.
Surface geology
Moon topography has been measured with laser altimetry and stereo image analysis. Its most noticeable topographic feature is the gigantic South-Pole-Aitken basin located about 2,240 km (1,390 mi) in diameter, the largest crater on the Moon and the second largest impact crater confirmed in the Solar System. At a depth of 13 km (8.1 miles), the floor is the lowest point on the surface of the Moon. The highest altitude of the Moon's surface lies directly to the northeast, and has been suggested may have been thicken by the impact of the oblique formation of the South Pole-Aitken basin. Other major impact hollows, such as Imbrium, Serenitatis, Crisium, Smythii, and Orientale, also have low and high elevations. The far side of the moon's surface averages about 1.9 km (1.2 mi) higher than the near side.
The discovery of the steep cliffs of errors by the Lunar Reconnaissance Orbiter shows that the Moon has shrunk in the last billion years, about 90 meters (300 feet). A similar shrink feature exists in Mercury.
Volcanic features
The plains of the dark moon and relatively unobtrusive, clearly visible to the naked eye, are called maria (Latin for "sea"; single mare ), as they were once believed to be filled with water ; they are now known as very dense pools of primal basaltic lava. Though similar to terrestrial basalt, the lunar basal has more iron and no minerals are converted by water. The majority of these lava erupt or flow into depression associated with impact basins. Several geological provinces containing volcanoes of shields and volcanoes of dorms are found near "maria".
Nearly all maria are on the near side of the Moon, and cover 31% of the near side surface, compared to 2% of the far side. This is thought to be due to the concentration of heat-generating elements below the crust on the near side, visible on the geochemical map obtained by the Lunar Prospector gamma ray spectrometer, which will cause the mantle base to heat, partially melt, rising to the surface and erupting.Most of the Moon's basal mare erupted during the Imbrian period, 3.0-3.5 billion years ago, although some of the radiometric date samples are as old as 4.2 billion years.Until recently, the youngest eruption, calculated by the calculation of the crater, was apparently only 1.2 billion years ago.In 2006, a study of Ina, a small depression in Lacus Felicatis, found features relatively dust-free, jagged, due to the lack of erosion by debris, debung infalling, seems to be only 2 million years old.Sunquake and gas release also show some advanced lunar activity.In 2014 NASA announced "widespread evidence of youth volcanism" in 7 0 irregular mare patches identified by the Lunar Reconnaissance Orbiter, some less than 50 million years old. This increases the likelihood of moon coats warmer than previously believed, at least on the near side where deeper crust is substantially warmer due to the greater concentration of radioactive elements. Just before this, evidence has been presented for 2-10 million years of young basaltic volcanism in the Lowell crater, the Orientale basin, located in the transition zone between the near and far side of the Moon. Initially a hotter coat and/or local enrichment of heat-generating elements in the mantle could be responsible for long activities as well on the far side of the Orientale valley.
The lighter-colored areas of the Moon are called terrae, or more commonly, in the highlands, because they are higher than most maria. They have been radiometrically dated to form 4.4 billion years ago, and may represent the plagioclase cumulates of the magma moon sea. Unlike the Earth, no large lunar mountains are believed to have formed as a result of tectonic events.
The concentration of maria on the Near Side is likely to reflect a much thicker crust of a plateau of the Far Side, which may have formed in the slow-speed impact of Earth's second moon some tens of millions of years after its formation.
Impact crater
Another major geological process that has affected the Moon's surface is the impact of the crater, with the crater formed when the asteroids and comets collide with the lunar surface. It is estimated there are about 300,000 craters wider than 1 km (0.6 mi) on the near side of the Moon alone. The geological time scale of the moon is based on the most prominent impact events, including Nectaris, Imbrium, and Orientale, structures characterized by several raised material rings, between hundreds and thousands of kilometers in diameter and associated with the vast apron of ejecta deposits that form the regional stratigraphic horizon. The lack of atmosphere, weather and recent geological processes means many of these craters are well preserved. Although only a few definite multi-ring basins are defined, they are useful for determining relative ages. Because crater impacts accumulate at an almost constant rate, calculating the number of craters per unit area can be used to estimate the age of the surface. The radiometric age of melted-impact rocks collected during the Apollo mission group between 3.8 and 4.1 billion years: this has been used to propose the End of the Great Bombing from impact.
The blanket above the Moon's crust is very comminuted (breaks into smaller particles) and impacts a gardening surface layer called regolith, formed by the impact process. The finer regolit, the moon soil of silicon dioxide glass, has a snow-like texture and a scent that resembles the spent gunpowder. The older surface regoliths are generally thicker than the younger surface: it varies in thickness from 10-20 km (6.2-12.4 mi) in the highlands and 3-5Ã, km (1.9-3, 1Ã, mi) in maria. Below the finely smoothed regolit layer is megaregolith , a very cracked bedrock layer several kilometers thick.
The comparison of high-resolution images obtained by the Lunar Reconnaissance Orbiter has shown contemporary crater-production levels much higher than previously thought. The secondary crater process caused by the distal ejecta is estimated to stir two centimeters of regolith a hundred times faster than the previously suggested model - on a time scale of 81,000 years.
moon circle
The moon arena is a mysterious feature found on the surface of the Moon. They are characterized by high albedo, appear to be genetically immature (ie relatively young regolithic optical characteristics), and have a form that is often tortuous. The shape is often emphasized by the low albedo region that blows in between the bright circles.
Water presence
Liquid water can not survive on the surface of the moon. When exposed to solar radiation, water quickly decomposes through a process known as photodissociation and disappears into space. However, since the 1960s, scientists have hypothesized that water ice can be precipitated by comets that have an impact or may be generated by oxygen-rich moon rock reactions, and hydrogen from the solar wind, leaving traces of water that may survive in cold, permanent shadows. crater at the poles on the Moon. Computer simulations show that up to 14,000 km 2 (5,400Ã, sqÃ, mi) of the surface may be in permanent shadow. The presence of the amount of water that can be used on the Moon is an important factor in making the lunar residence as a cost-effective plan; alternative water transport from Earth will be very expensive.
Years later, signs of water have been found on the lunar surface. In 1994, a bistatic radar experiment located on the Clementine spacecraft indicated the presence of small, frozen water pockets near the surface. However, later radar observations by Arecibo, suggesting this finding is better to be a stone removed from a young impact crater. In 1998, the neutron spectrometer on the Lunar Prospector spacecraft showed that high hydrogen concentrations were present in the first meter of depth in the regolith near the polar regions. Volcanic lava beads, brought back to Earth on board the Apollo 15, show a small amount of water on the inside.
The 2008 Chandrayaan-1 spacecraft has since confirmed the presence of surface water ice, using the Moon Mineralogy Mapper on-board. The spectrometer observes the general absorption pathway for hydroxyl, in reflected sunlight, providing ample evidence of ice, on the lunar surface. The spacecraft shows that the concentration may reach 1,000 ppm. In 2009, LCROSS sent 2,300 kg (5,100 lb) crashes to permanent shadow polar craters, and detected at least 100 kg (220 lb) of water in a clump of material released. Another examination of the LCROSS data shows the amount of water detected to be closer to 155 Ã, Â ± 12Ã, kg (342 Ã, Â ± 26Ã, lb).
In May 2011, 615-1410 ppm of water in melted melt in a 74220 moon sample was reported, the famous "famous orange-glass" titanium well-known from volcanic origin collected during the Apollo 17 mission in 1972. Inclusion was formed during an explosive eruption on the Moon around 3.7 billion years ago. This concentration is proportional to the magma in the upper mantle of the Earth. Despite considerable interest, this announcement provides little comfort for candidate colonists of the moon - samples come from several kilometers below the surface, and inclusion is very difficult to access so it took 39 years to find them with the state of the ion-art microprobe instrument.
Field of gravity
The Moon's gravity field has been measured by tracking the Doppler shift from radio signals emitted by an orbiting spacecraft. The main moon's gravity feature is mascons, a large positive gravitational anomaly associated with some giant impact basins, in part due to the lava flow of solid basalt lava that filled the hollow. Anomalies greatly affect the orbits of spacecraft about the Moon. There are some puzzles: lava flows themselves can not explain all the signs of gravity, and some mascons exist that are not associated with mare volcanism.
Magnetic field
The moon has an external magnetic field of about 1-100 nanoteslas, less than one hundredth of the earth. The current moon does not have a global dipolar magnetic field and only has a magnetization of the crust, probably obtained at the beginning of its history when the dynamo is still operating. Alternatively, some residual magnetization may be derived from the transient magnetic field generated during major impacts through the expansion of the resulting plasma clouds in the ambient magnetic field. This is supported by the apparent location of the largest magnetic crust magnetization near the antipodes from the giant impact basin.
Atmosphere
The moon has a very tenuous atmosphere that is almost empty, with a total mass of less than 10 metric tons (9.8 tons long, 11 tons short). The pressure of this small mass surface is about 3 ÃÆ'â € "10 -15 Ã, atm (0.3 nPa); it varies with the lunar day. Its sources include outgassing and sputtering, the product of a moon land bombardment by solar wind ions. The detected elements include sodium and potassium, produced by sputtering (also found in the atmosphere of Mercury and Io); helium-4 and neon from the solar wind; and argon-40, radon-222, and polonium-210, were defeated after their creation by radioactive decay in the crust and mantle. The absence of neutral species (atoms or molecules) such as oxygen, nitrogen, carbon, hydrogen and magnesium, present in the regolith, is not understood. Water vapor has been detected by Chandrayaan-1 and is found to vary with latitude, with a maximum of ~ 60-70 degrees; it may result from sublimation of water ice in the regolith. These gases either return to the regolith because of the gravity of the Moon or lost into space, either through the pressure of solar radiation or, if they are ionized, by being swept away by the solar wind magnetic field.
Dust
Permanent asymmetrical moon clouds are present around the Moon, created by tiny particles of comets. Estimates of 5 tons of comet particles attack the Moon's surface every 24 hours. The particles are attacking the Moon's surface that releases moon dust over the Moon. Dust is on top of the Moon about 10 minutes, takes 5 minutes to ride, and 5 minutes to fall. On average, 120 kilograms of dust is present on top of the Moon, rising to 100 kilometers above the surface. The dust measurements were carried out by LADEE's Lunar Dust EXPERiment (LDEX), between 20 and 100 kilometers above the surface, over a six-month period. LDEX detects an average of one dust particle 0.3 micrometers per minute. The number of dust particles peaks during Geminid, Quadrantid, Northern Taurid, and Centaurid Omicron meteor shower, when Earth, and Moon, pass through the debris of comets. The clouds are asymmetrical, denser near the boundary between the moon and the night on the Moon.
The atmosphere is thicker then
In October 2017, NASA scientists at the Marshall Space Flight Center and Lunar and Planetary Institute in Houston announced their findings, based on the Moon moon sample study taken by Apollo missions, that the Moon once had a relatively thick atmosphere for a period. 70 million years between 3 and 4 billion years ago. This atmosphere, which comes from gas coming out of the volcanic moon eruption, is twice as thick as today's Mars. The atmosphere of the ancient moon was finally disarmed by the solar wind and disappeared into space.
Seasons
The slope of the Moon's axis with respect to the ecliptic is only 1,5424 Â °, much less than 23.44 Â ° Earth. Therefore, the Moon's solar lighting varies much less with the seasons, and topographic details play an important role in seasonal effects. From a picture taken by Clementine in 1994, it appears that four mountain regions on the edge of Peary Crater at the Moon's north pole may remain illuminated throughout the lunar day, creating a peak of eternal light. There is no such area in the south pole. Similarly, there are places that remain in the permanent shadow at the bottom of many polar craters, and this "crater of eternal darkness" is very cold: Lunar Reconnaissance Orbiter measures the lowest summer temperatures in craters south of the poles on 35Ã,K (-238Ã, Â ° C; -397Ã, Â ° F) and only 26Ã,K (-247Ã, Â ° C; -413Ã, Â ° F) close to the winter solstice at the north pole of Hermite Crater. It is the coldest temperature in the Solar System ever measured by a spacecraft, cooler than the surface of Pluto. The average surface temperature of the Moon is reported, but temperatures in different regions will vary greatly depending on whether they are in sunlight or shadow.
Relationships to Earth
Orbit
The moon makes a complete orbit around the Earth with respect to the stars fixed about once every 27.3 days (sidereal period). However, as the Earth moves in its orbit around the Sun at the same time, it takes longer for the Moon to show the same phase to Earth, which is about 29.5 days (its synodic period). Unlike most satellites on other planets, the Moon orbits closer to the ecliptic plane than to the planets in the equator plane. The Moon's orbit is subtly disturbed by the Sun and Earth in many small, intricate and interacting ways. For example, the orbital plane of the Moon gradually rotates every 18.61 years, affecting other aspects of the motion of the moon. This continued effect is mathematically explained by Cassini's law.
Relative size
The Moon is relatively large against Earth: Its diameter is a quarter and its mass 1/81 of Earth. This is the largest moon in the Solar System relative to the size of the planet, although Charon is larger than the Pluto dwarf planet, on the 1/9 mass of Pluto. Earth and the Moon barycentre, their common mass center, lies 1,700 km (1,100 mi) (about a quarter of Earth's radius) beneath the earth's surface.
The Earth revolves around Earth-Moon barycentre once a sidereal month, with 1/81 the speed of the Moon, or about 12.5 meters (41Ã, ft) per second. This movement is superimposed on a much larger Earth revolution around the Sun at a speed of about 30 kilometers (19 mi) per second.
Appearance from Earth
The moon is in synchronous rotation because it orbits the Earth; rotates about its axis around the same time to orbit the Earth. These results always keep a face almost identical to the Earth. However, due to the effects of libration, about 59% of the surface of the Moon can actually be seen from Earth. The side of the Moon that faces the Earth is called the near side, and the opposite side. The far side is often inaccurately called the "dark side", but is actually illuminated as often as the near side: once every 29.5 Earth days. During the new moon, the near side is dark.
The moon once rotates at a faster rate, but at the beginning of its history, its spins slow down and become locked tidally in this orientation as a result of the frictional effects associated with tidal deformations caused by Earth. Over time, the Moon's rotation energy on its axis is lost as heat, until there is no Moon's rotation relative to Earth. In 2016, planetary scientists, using data collected on NASA's Lunar Prospector mission much earlier, discovered two hydrogen-rich regions on the opposite side of the Moon, possibly in the form of water ice. It is estimated that these patches are poles of the Moon billions of years ago, before they are locked tightly to Earth.
The moon has a very low albedo, making it a slightly lighter reflection than the worn asphalt. Nevertheless, this is the brightest object in the sky after the Sun. This is partly due to increased brightness of opposition waves; The moon in the quarter phase is only a tenth of a light, not half light, as in the full moon. In addition, the firmness of color in the visual system re-calibrates the relationship between the color of the object and its surroundings, and since the surrounding sky is relatively dark, the sunlit Moon is considered a bright object. The full moon's edge is as bright as its center, with no darkening of the branches, due to the reflective nature of the moon's soil, which reflects more light toward the Sun than in the other direction. The moon appears larger when it is close to the horizon, but it is a purely psychological effect, known as the illusion of the moon, first described in the 7th century BC. The full Moon angle diameter is about 0.52  ° (average) in the sky, approximately the same size as the Sun (see Ã,§ Eclipses).
The highest height of the Moon at the summit varies by phase and time. The full moon is currently northern most during winter. The nodal cycle of 18.61 years has an influence on the lunar halt. When the ascending nodes of the lunar orbit are in the vernal equinox, the lunar declination can reach up to plus or minus 28 Â ° every month. This means the Moon may pass overhead when viewed from the latitude to 28 ° north or south (from the Equator), not just 18 °. The crescent moon's orientation also depends on the latitude of the vision location; an observer in the tropics can see the crescent-shaped Moon. The moon is visible for two weeks every 27.3 days in the North and South Poles. Zooplankton in the Arctic uses the moonlight when the Sun is under the horizon for months.
Distance between the Moon and Earth varies from 356,400 km (221,500 mi) to 406,700 km (252,700 mi) in perigee (nearest) and apogee (farthest), respectively. On November 14, 2016, it is closer to Earth when it is in full phase than since 1948, 14% closer than the farthest position in apogee. Reported to be "supermoon", this closest point coincides within an hour of the full moon, and it's 30% more luminous than the moment at its greatest distance because its diameter is 14% larger and . At lower levels, the human perception of the brightness reduction as a percentage is provided by the following formula:
When the actual reduction is 1.00/1.30, or about 0.770, the perceived reduction is about 0.877, or 1.00/1.14. This provides a maximum increase of 14% between apogee and perigee months in the same phase.
There is a historical controversy about whether the features on the surface of the Moon change over time. Today, many of these claims are considered illusions, resulting from observations under different lighting conditions, poor astronomical vision, or inadequate images. However, outgassing occurs occasionally and can be responsible for a fraction of the transient phenomenon of the reported moon. Recently, it has been suggested that about 3 km (1.9 mi) of surface diameter area of ​​the moon has been modified by gas release events about a million years ago.
The appearance of the Moon, like the Sun, can be affected by Earth's atmosphere. The common optical effect is the halo ring 22 Â °, formed when Moon light is refracted through a high cirrostratus cloud crystal ice, and smaller coronal rings when the Moon is seen through thin clouds.
Area yang diterangi dari bola yang terlihat (tingkat iluminasi) diberikan oleh , di mana adalah pemanjangan (yaitu, sudut antara Bulan, pengamat (di Bumi) dan Matahari).
Efek pasang surut
The gravitational attraction that the masses possess for each other diminishes inversely with the squared distances of the masses to each other. As a result, the slightly larger magnitude that the Moon has for the Earth's side closest to the Moon, compared to the Earth's opposite part of the Moon, produces tidal forces. Tidal forces affect both the earth's crust and the oceans.
The most noticeable effect of tidal forces is to cause two bulges in the Earth's oceans, one on the side facing the Moon and the other on the opposite side. This produces a high sea level called sea tides. As the Earth rotates on its axis, one of the sea spikes (tide) is held in place "under" the Moon, while the other waves are opposite. As a result, there are two high pairs, and two low tides in about 24 hours. Because the Moon orbits Earth in the same direction as the Earth's rotation, high waves occur every 12 hours and 25 minutes; 25 minutes is due to the time of the Moon to orbit the Earth. The sun has the same tidal effect on Earth, but its appeal is only 40% of the Sun; Sun and Moon interactions are responsible for spring and sea water. If Earth is a water world (one without continents) it will produce only one meter waves, and the waves will be very predictable, but the ocean waves are heavily modified by other effects: frictional friction water into the Earth's rotation through the ocean floor, inertia of water movement, an ocean that grows in shallow ground, spills of water between different ocean basins. Consequently, the tidal time at most points on Earth is the product of the observations described, incidentally, by theory.
While gravity causes the acceleration and movement of oceanic oceans of the Earth, the gravitational coupling between the Moon and the Earth's solid body is mostly elastic and plastic. The result is a further tidal effect of the Moon on Earth that causes a bulge from the nearest density of the Earth's Moon which acts as a torque in opposition to the Earth's rotation. This momentum revolves "flows" and the kinetic energy of the rotation of the Earth's spin, slowing the Earth's rotation. The angular momentum, lost from Earth, is transferred to the Moon in a process (which is confusingly known as tidal acceleration), which lifts the Moon into higher orbits and results in lower orbital velocities about the Earth. Thus the distance between Earth and the Moon increases, and the Earth's spin slows down as a reaction. Measurements from the remaining laser reflectors during Apollo missions (month-range experiments) have found that the Moon's distance increases by 38 mm (1.5 inches) per year (approximately the rate of growth of human fingernails). The atomic clock also shows that Earth's day extends about 15 microseconds annually, slowly increasing the rate at which UTC is adjusted by leap seconds. Left to run its course, the pull of this wave will continue until the Earth's spin and Moon's orbital period matches, creating a tidal lock between the two. As a result, the Moon will be suspended in the sky above one meridian, as it currently happens with Pluto and its moon Charon. However, the Sun will be the red giant that struck the Earth-Moon system long before this incident.
In the same way, the moon's surface has ups and downs about 10 cm (4 in) amplitudes for 27 days, with two components: one fixed because of Earth, because they are in sync rotation, and components that vary from the Sun. Earth-induced components arise from libration, the result of the eccentricity of the Moon's orbital (if the Moon's orbit is perfectly circular, there will only be solar waves). Libration also changes the angle from which the Moon is visible, allowing a total of about 59% of its surface to be viewed from the Earth over time. The cumulative effect of stress built by this tidal force produces moonquakes. Moonquake is much rarer and weaker than earthquakes, although full moons can last up to an hour - much longer than earthquakes - in the absence of water to dampen seismic vibrations. The existence of the moonquake is an unexpected discovery of a seismometer placed on the Moon by Apollo astronauts from 1969 to 1972.
Eclipse
Eclipses only occur when the Sun, Earth, and Moon are all in a straight line (called "syzygy"). The solar eclipse occurs on the new moon, when the Moon is between the Sun and the Earth. In contrast, a lunar eclipse occurs on a full moon, when the Earth is between the Sun and the Moon. The size of the Moon looks about the same as the Sun, with both seen at almost one and a half degrees. The sun is much larger than the Moon but the distance is much larger that gives the same size as the Moon is much closer and much smaller from the perspective of Earth. Variations in clear size, because of the non-circle orbit, are almost the same, though they occur in different cycles. This allows the total (with the Moon to appear larger than the Sun) and annular (with the Moon appearing smaller than the Sun) solar eclipse. In a total eclipse, the Moon completely covers the sun's disk and the sun's corona becomes visible to the naked eye. Because the distance between the Moon and Earth is very slow increases with time, the Moon's angular diameter decreases. Also, as it evolves into a red giant, the size of the Sun, and its clear diameter in the sky, it slowly rises. The combination of these two changes means that hundreds of millions of years ago, the Moon will always cover the Sun on a solar eclipse, and no annular eclipses are possible. Likewise, hundreds of millions of years in the future, the Moon will no longer cover the Sun completely, and a total solar eclipse will not happen.
Since the Moon's orbit around Earth tends to be around 5,145 Â ° (5 Â ° 9 ') into Earth's orbit around the Sun, the eclipse does not occur in every full and new month. In order for an eclipse to occur, the Moon must be near the junction of two orbits. The periodicity and recurrence of the solar eclipse by the Moon, and the Moon to Earth, is described by saros, which has a period of about 18 years.
Because the Moon constantly blocks our view of the half-circle of the sky, occult-related phenomena occur when a bright star or planet passes behind the Moon and is encrypted: hidden from view. In this way, the solar eclipse is the magic of the Sun. Since the Moon is relatively close to the Earth, the occultation of individual stars is not seen everywhere on the planet, or at the same time. Because of the precession of the lunar orbit, each year different stars are circumcised.
Observation and exploration
Ancient and medieval studies
The understanding of the Moon cycle is an early development of astronomy: by the 5th century BC Babylonian astronomers have recorded the 18-year cycle of Saros lunar eclipse, and Indian astronomers have described the monthly extension of the Moon. Chinese astronomer Shi Shen (4th century BC) gives instructions for predicting solar and lunar eclipses. Then, the physical shape of the Moon and the cause of the moon's light become understood. The ancient Greek philosopher Anaxagoras (428 BC) argued that the Sun and the Moon are equally gigantic, and the latter reflects light from the first. Although the Chinese of the Han Dynasty believe that the Moon is the energy equated with the qi , the theory of 'the effects of radiation' they also recognize that the light of the Moon is only a reflection of the Sun, and Jing Fang (78-37 BC) notes the sphere month. In the 2nd century, Lucian wrote the novel A True Story , in which the heroes traveled to the Moon and met with the inhabitants. In 499 AD, Indian astronomer Aryabhata mentioned in his book Aryabhatiya that reflects sunlight is the cause of the Moon's light. Astronomer and physicist Alhazen (965-1039) discovered that sunlight is not reflected from the Moon like a mirror, but the light is emitted from every part of the sunlit Moon's surface in all directions. Shen Kuo (1031-1095) of the Song dynasty created an allegory that equated waxing and waning the Moon to a round ball of reflective silver which, when doused with white powder and viewed from the side, would look like a crescent moon.
In the description of Aristotle (384-322 B.C.) of the universe, the Moon marks the boundary between the spheres of mutable elements (earth, water, air and fire), and the imperishable stars of the ether, an influential philosophy that will dominated for centuries.. However, in the 2nd century BC, Seleucus of Seleucia correctly theorizes that the tides are due to the attraction of the Moon, and that their altitude depends on the position of the Moon relative to the Sun. In the same century, Aristarchus calculated the size and distance of the Moon from Earth, obtaining a value of about twenty times the radius of the Earth for distance. These figures are greatly enhanced by Ptolemy (90-168 AD): the values ​​of an average distance of 59 times the radius of the Earth and the diameter of 0.292 Earth diameter close to the correct value of about 60 and 0.273 respectively. Archimedes (287-212 BC) designed a planetarium that could calculate the motions of the Moon and other objects in the Solar System.
During the Middle Ages, before the invention of the telescope, the Moon became known as a ball, although many believed it was "very smooth".
In 1609, Galileo Galilei drew one of the first telescopic images of the Moon in his book Sidereus Nuncius and noted that it was not smooth but had mountains and craters. Moon telescopic mapping followed: later in the 17th century, the efforts of Giovanni Battista Riccioli and Francesco Maria Grimaldi led to the monthly feature naming system used today. The more exact 1834-36 With a spaceship
20th century
Soviet Mission
The Cold War-inspired Space War between the Soviet Union and the United States encouraged an accelerated interest in Moon exploration. Once the launcher has the necessary capabilities, these countries send unmanned probes on both flyby and impact/landing missions. The spacecraft from the Soviet Union program is the first to achieve a number of goals: following three nameless missions, failed in 1958, the first man-made object to escape Earth's gravity and pass near the Moon is Luna 1 ; the first man-made object to affect the lunar surface was Luna 2 , and the first of the typically clogged Moon portraits were made by Luna 3 , all in 1959.
The first spacecraft to perform a successful lunar landing was Luna 9 and the first unmanned orbiting vehicle of the Moon was Luna 10 , both in 1966. Samples of rock and soil were brought back to Earth by three Luna examples of return missions ( Luna 16 in 1970, Luna 20 in 1972, and Luna 24 in 1976), which returned a total of 0.3 kg. Two pioneering robot rovers landed on the Moon in 1970 and 1973 as part of the Soviet Lunokhod program.
Luna 24 is the last Soviet/Russian mission to the Moon.
United States Mission
During the late 1950s at the height of the Cold War, the US Army undertook a covert feasibility study proposing the construction of a manned military post on the Moon called Project Horizon with the potential to undertake various missions from scientific research to nuclear Earth bombing. The study included the possibility of conducting a month-long nuclear test. The Air Force, which at the time competed with the Army for a leading role in the space program, developed a similar plan called Lunex. However, both of these proposals were finally passed because the space program was transferred from the military to a NASA civilian institution.
Following the commitment of President John F. Kennedy in 1961 to a manned lunar landfall before the end of the decade, the United States, under the leadership of NASA, launched a series of unmanned probes to develop an understanding of the lunar surface in preparation for manned missions: The Ranger Propulsion Laboratory Jet Program produces images first close-up; the Lunar Orbiter program produces a map of the entire Moon; The Surveyor program landed the first spacecraft four months after Luna 9 . The manned Apollo program is developed in parallel; after a series of unmanned and manned tests of the Apollo spacecraft in Earth orbit, and triggered by a potential Soviet lunar flight, in 1968, Apollo 8 performed its first manned mission into a lunar orbit. The next landing of the first humans on the Moon in 1969 was seen by many as the culmination of the Space Race.
Neil Armstrong became the first person to walk on the Moon as the commander of the American mission Apollo 11 by setting the first foot on the Moon at 02:55 UTC on July 21, 1969. An estimated 500 million people worldwide witnessed the transmission by Apollo TV cameras, the largest television viewer for broadcast directly at that time. Apollo 11 to 17 missions (except Apollo 13, which canceled planned lunar landings) produced 380.05 kilograms (837.87 lb) of moon and soil rocks in 2,196 separate samples. The landing and restoration of the American Moon was made possible by technological advances in the early 1960s, in areas such as ablation chemistry, software engineering, and atmospheric re-entry technologies, and by highly competent management in the huge technical field.
A package of scientific instruments mounted on the lunar surface during all Apollo landings. Long-lived instrument stations, including heat flow probes, seismometers, and magnetometers, were installed at Apollo 12, 14, 15, 16 and 17 landing sites. The direct data transmission to Earth ended in late 1977 due to budget considerations, but because lunar laser stations ranged the cavities of the retroreflector cube are passive instruments, they are still used. Starting from the station is routinely performed from Earth-based stations with a few centimeter accuracy, and data from this experiment is used to place constraints on the size of the lunar core.
1980s-2000
After the first Month race there were almost silent years but beginning in the 1990s, more countries have been involved in direct exploration of the Moon. In 1990, Japan became the third country to put the spacecraft into orbit the moon with the Hiten spacecraft. The spacecraft issued a smaller probe, Hagoromo , in lunar orbit, but the transmitter failed, preventing further scientific use of the mission. In 1994, the US sent the Joint Department of Defense/NASA spacecraft Clementine to the moon's orbit. The mission obtained the first global topographic map of the Moon, and the first global multispectal image of the lunar surface. This was followed in 1998 by the Lunar Prospector mission, whose instruments indicate the presence of excess hydrogen at the lunar pole, which is likely due to the presence of ice water in the upper few meters of the regolith inside the permanent perforated crater.
India, Japan, China, the United States and European Space Agency each send out the Moon orbiter, and especially the ISRO Chandrayaan-1 have contributed to confirm the discovery of moon water ice in the permanent shadow crater at the poles and tied to regolith month. The post-Apollo era has also witnessed two exploratory missions: the late Soviet Lunokhod mission in 1973, and the ongoing Chang'e 3 mission in China, which deployed Yutu's exploration on December 14, 2013. The moon is still under the Free Space Agreement to all countries to explore for peaceful purposes.
21st century
The European spacecraft SMART-1 , the second ion-powered spacecraft, was in orbit of the moon from November 15, 2004 to the impact of the moon on September 3, 2006, and made the first detailed survey of chemical elements on the moon the. surface.
The ambitious Lunar China Lunar Exploration Program begins with Chang'e 1 , which successfully circled the Moon from November 5, 2007 until its monthly impact is controlled on March 1, 2009. It acquires the full image map of the Moon. Chang'e 2 , starting in October 2010, reaching the Moon faster, charting the Moon at higher resolution over a period of eight months, then leaving the moon's orbit for extended stay on Earth-Sun Point L2 Lagrangian , before finally performing flyby 4148 Toutatis asteroid on December 13, 2012, and then heading into space. On December 14, 2013, Chang'e 3 landed a lunar lander to the surface of the Moon, which in turn distributed a moon rover, named Yutu (Chinese: ??; literally "Jade Rabbit "). This is the first lunar soft landing since Luna 24 in 1976, and the first lunar explorer mission since Lunokhod 2 in 1973. China intends to launch another exploration mission ( Chang 'e 4 ) before 2020, followed by a sample repayment mission ( Chang'e 5 ) shortly thereafter.
Between October 4, 2007 and June 10, 2009, the Japan Space Exploration Agency Kaguya Mission (Selene) , the Moon orbiter is equipped with a high definition video camera, and two small radio transmitting satellites, obtained geophysical data moon and took a movie the first high definition from outside Earth's orbit. India's first lunar mission, Chandrayaan I, orbited from 8 November 2008 until the disappearance of contacts on August 27, 2009, created a high-resolution geo-chemical, mineralogical and photographic map of the lunar surface, and confirmed the presence of water molecules on the moon's soil. The Indian Space Research Organization plans to launch Chandrayaan II in 2013, which will include Russia's robotic lunar rover. However, the failure of Russia's Fobos-Grunt mission has delayed this project.
USA jointly launched the Lunar Reconnaissance Orbiter (LRO) and LCROSS drill and observation follow-up watchdog on June 18, 2009; LCROSS completed its mission by making a planned and widely observed impact on Cabeus crater on October 9, 2009, while LRO is currently in operation, obtaining proper lunar altimetry and high resolution. parable. In November 2011, LRO passed the large and bright Aristarchus crater. NASA released a crater photo on December 25, 2011.
Two NASA GRAIL spacecraft began orbiting the Moon around January 1, 2012, on a mission to learn more about the internal structure of the Moon. The NASA LADEE probe, designed to study the lunar exposure, reaches orbit on October 6, 2013.
The upcoming moon missions include Russia Luna-Glob : an unmanned lander with a seismometer set, and an orbiter based on the failed mission of Fobos-Grunt . Privately funded monthly explorations have been promoted by Google Lunar X Prize, announced September 13, 2007, which offers US $ 20 million to anyone who can land a robot rover on the Moon and meet other specified criteria. Shackleton Energy Company is building a program to set up operations at the moon's south pole to harvest water and supply their Propelan Depo.
NASA began planning to continue the manned mission following a call by US President George W. Bush on January 14, 2004 for a manned mission to the Moon in 2019 and the construction of a moon base in 2024. The Constellation program is funded and construction and testing begins with manned spacecraft and vehicles launchers, and design studies for lunar bases. However, the program has been canceled to support a manned asteroid landing in 2025 and a manned Mars orbit by 2035. India also expressed its hope to send a manned mission to the Moon by 2020.
On February 28, 2018, SpaceX, Vodafone, Nokia, and Audi announced a collaboration to install 4G wireless communications network on the Moon, with the aim of broadcasting live footage on the surface to Earth.
Planning a commercial mission
In 2007, the X Prize Foundation with Google launched the Google Lunar X Prize to drive the commercial effort into the Moon. A $ 20 million prize will be awarded to the first private company to get to the Moon with a robotic landing at the end of March 2018, with an additional prize worth $ 10 million for further milestones. In August 2016, 16 teams participated in the competition. In January 2018 the foundation announced that the prize will be unclaimed because no finalist team can make a launch effort on the deadline.
In August 2016, the US government granted permission to start an Express Moon in the US to land on the Moon. This marks the first time a private company has been granted the right to do so. This decision is considered a precedent that helps define the regulatory standards for future commercial activity in space, as so far the operations of the company are limited to being in or around Earth.
Astronomy of the Moon
Over the years, the Moon has been recognized as an excellent site for telescopes. It's relatively close; seeing astronomy is not a concern; Certain craters near the poles are permanently dark and cold, and thus very useful for infrared telescopes; and a radio telescope on the far side will be protected from Earth radio chatter. The moon soil, though poses a problem for every moving part of the telescope, can be mixed with carbon nanotubes and epoxies and is used in the construction of mirrors up to 50 meters in diameter. A moon zenith telescope can be made cheaply with ionic liquids.
In April 1972, the Apollo 16 mission recorded various ultrasound images of astronomy and spectra in Ultraviolet/Spectrograph Cameras.
Legal status
Although Luna was landing the banner of the Soviet Union on the Moon, and the US flag was symbolically planted at their landing site by Apollo astronauts, no nation claimed ownership of any part of the Moon's surface. Russia and the United States are parties to the 1967 Space Treaty, which defines the Moon and all the outer space as "the province of all humanity". This Agreement also limits the use of the Moon for peaceful purposes, explicitly prohibiting the installation of military and weapons of mass destruction. The 1979 Treaty was made to limit the exploitation of the Moon's resources by one nation, but by November 2016, signed and ratified by only 18 countries, no one was involved in human space exploration launched alone or had plans to do so. Although some individuals have made claims to the Moon in whole or in part, nothing is considered credible.
In culture
Mythology
A 5,000-year-old rock carvings in Knowth, Ireland, can represent the Moon, which will be the earliest depiction found. The contrast between the brighter plateau and the darker maria creates patterns seen by different cultures such as Humans on the Moon, rabbits and buffalo, among others. In many prehistoric and ancient cultures, the Moon is personified as a god or other supernatural phenomenon, and the Moon's astrological view continues to be propagated today.
In Proto-Indo-European religion, the moon is personified as a male god * Meh 1 not . The ancient Sumerians believed that the Moon was the god Nanna, who was the father of Inanna, the goddess of the planet Venus, and Utu, the sun god. Nanna later became known as SÃÆ'®n, and was primarily associated with magic and magic. In Greco-Roman mythology, the Sun and the Moon are represented as male and female, respectively (Helios/Sol and Selene/Luna); this is a unique development for the eastern Mediterranean and the traces of previous male moon gods in the Greek tradition preserved in the figure of Menelaus.
In Mesopotamian iconography, the crescent moon is the main symbol of Nanna-SÃÆ'®n. In the art of ancient Greece, the Moon Selene goddess was represented wearing a sickle on its head cap in a setting that reminded the horns. The arrangement of stars and crescent moon also returns to the Bronze Age, representing the Sun and the Moon, or the Moon and the planet Venus, in combination. It came to represent the goddess Artemis or Hecate, and through Hecate's patronage came to be used as a Byzantine symbol.
The iconography tradition represents the Sun and the Moon with a face developed at the end of the medieval period.
Separation of the moon (Arabic: ?????? ????? ?) Is a miracle associated with Muhammad.
Calendars
The regular phase of the Moon makes it a very comfortable watch, and the waxing and fading period forms the basis of many of the oldest calendars. Tally sticks, curvy bones dating as far back as 20-30,000 years ago, are believed by some to mark the phases of the Moon. Month ~ 3
Source of the article : Wikipedia
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