50 Facts About Moon


The Moon is a planetary-mass object that formed a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term.

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The Moon is tidally locked to Earth, which means that the length of a full rotation of the Moon on its own axis causes its same side to always face Earth, and the somewhat longer lunar day is the same as the synodic period.

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The near side of the Moon is marked by dark volcanic maria, which fill the spaces between bright ancient crustal highlands and prominent impact craters.

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The first artificial object to reach the Moon was the Soviet Union's Luna 2 uncrewed spacecraft in 1959; this was followed by the first successful soft landing by Luna 9 in 1966.

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Usual English adjective pertaining to the Moon is "lunar", derived from the Latin word for the Moon, luna.

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Gravitational capture of a pre-formed Moon depends on an unfeasibly extended atmosphere of Earth to dissipate the energy of the passing Moon.

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These simulations show that most of the Moon derived from the impactor, rather than the proto-Earth.

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Moon is a very slightly scalene ellipsoid due to tidal stretching, with its long axis displaced 30° from facing the Earth, due to gravitational anomalies from impact basins.

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The whole surface area of the Moon is about 38 million square kilometers, slightly less than the area of the Americas.

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Moon is a differentiated body that was initially in hydrostatic equilibrium but has since departed from this condition.

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Moon is the second-densest satellite in the Solar System, after Io.

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Moon has an external magnetic field of generally less than 0.

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Therefore, the surface gravity of the Moon is about half of the surface gravity of Mars and about a sixth of Earth's.

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Topography of the Moon has been measured with laser altimetry and stereo image analysis.

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The highest elevations of the Moon's surface are located directly to the northeast, which might have been thickened by the oblique formation impact of the South Pole–Aitken basin.

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Discovery of fault scarp cliffs suggest that the Moon has shrunk by about 90 metres within the past billion years.

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Since the Moon doesn't have tectonic plates, its tectonic activity is slow and cracks develop as it loses heat.

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Lighter-colored regions of the Moon are called terrae, or more commonly highlands, because they are higher than most maria.

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Major geologic process that has affected the Moon's surface is impact cratering, with craters formed when asteroids and comets collide with the lunar surface.

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The presence of usable quantities of water on the Moon is an important factor in rendering lunar habitation as a cost-effective plan; the alternative of transporting water from Earth would be prohibitively expensive.

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Moon makes a complete orbit around Earth with respect to the fixed stars, its sidereal period, about once every 27.

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The Moon's orbit is subtly perturbed by the Sun and Earth in many small, complex and interacting ways.

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Gravitational attraction that Earth and the Moon exert on each other manifests in a slightly greater attraction on the sides of closest to each other, resulting in tidal forces.

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Since the Moon is orbiting the Earth in the same direction of the Earth's rotation, the high tides occur about every 12 hours and 25 minutes; the 25 minutes is due to the Moon's time to orbit the Earth.

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Thus the distance between Earth and Moon is increasing, and the Earth's rotation is slowing in reaction.

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Moon originally rotated at a faster rate, but early in its history its rotation slowed and became tidally locked in this orientation as a result of frictional effects associated with tidal deformations caused by Earth.

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Apparent orientation of the Moon depends on its position in the sky and the hemisphere of the Earth from which it is being viewed.

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Moon has an exceptionally low albedo, giving it a reflectance that is slightly brighter than that of worn asphalt.

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Moon does appear larger when close to the horizon, but this is a purely psychological effect, known as the Moon illusion, first described in the 7th century BC.

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On 14 November 2016, the Moon was at full phase closer to Earth than it had been since 1948.

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The apparent size of the Moon is roughly the same as that of the Sun, with both being viewed at close to one-half a degree wide.

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One of the earliest-discovered possible depictions of the Moon is a 5000-year-old rock carving Orthostat 47 at Knowth, Ireland.

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Ancient Greek philosopher Anaxagoras reasoned that the Sun and Moon were both giant spherical rocks, and that the latter reflected the light of the former.

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Telescopic mapping of the Moon followed: later in the 17th century, the efforts of Giovanni Battista Riccioli and Francesco Maria Grimaldi led to the system of naming of lunar features in use today.

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The Cold War fueled a closely followed development of the launch systems by the two states, resulting in the so-called Space Race and its later phase the Moon Race, accelerating efforts and interest in exploration of the Moon.

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Spacecraft from the Soviet Union's Luna program were the first to accomplish a number of goals: following three unnamed, failed missions in 1958, the first human-made object to escape Earth's gravity and pass near the Moon was Luna 1 in 1959; the first human-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.

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Between 2004 and 2006 the first spacecraft by the European Space Agency (SMART-1) reached the Moon, recording the first detailed survey of chemical elements on the lunar surface.

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The U S developed plans for returning to the Moon beginning in 2004, which resulted in several programs.

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Scholar Alice Gorman asserts that, although the Moon is inhospitable, it is not dead, and that sustainable human activity would require treating the Moon's ecology as a co-participant.

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Space debris beyond Earth around the Moon has been considered as a future challenge with increasing numbers of missions to the Moon, particularly as a danger for such missions.

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Beside the remains of human activity on the Moon, there have been some intended permanent installations like the Moon Museum art piece, Apollo 11 goodwill messages, six Lunar plaques, the Fallen Astronaut memorial, and other artifacts.

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Many years, the Moon has been recognized as an excellent site for telescopes.

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Moon has been a sight of Earth observation, particularly culturally as in the imagery called Earthrise.

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Only instances of humans living on the Moon have taken place in an Apollo Lunar Module for several days at a time.

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The 1979 Moon Agreement was created to elaborate, and restrict the exploitation of the Moon's resources by any single nation, leaving it to a yet unspecified international regulatory regime.

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In 2021 the Declaration of the Rights of the Moon was created by a group of "lawyers, space archaeologists and concerned citizens", drawing on precedents in the Rights of Nature movement and the concept of legal personality for non-human entities in space.

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The counting of the days between the Moon's phases gave eventually rise to generalized time periods of the full lunar cycle as months, and possibly of its phases as weeks.

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Furthermore, association of time with the Moon can be found in religion, such as the ancient Egyptian temporal and lunar deity Khonsu.

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Contemporarily the Moon has been seen as a place for economic expansion into space, with missions prospecting for lunar resources.

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The Moon has long been associated with insanity and irrationality; the words lunacy and lunatic are derived from the Latin name for the Moon, Luna.

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