Far side of the Moon.

The far side of the Moon is the lunar hemisphere that is permanently turned away from the Earth. This face is not visible because the rotation of the Moon about its axis is synchronized with its orbital period. This lock-step synchronization was achieved by the tidal forces between Earth and the Moon. Download high resolution version (1719x1719, 311 KB) Original Caption Released with Image About 50,000 Clementine images were processed to produce the four orthographic views of the Moon. ... Download high resolution version (1719x1719, 311 KB) Original Caption Released with Image About 50,000 Clementine images were processed to produce the four orthographic views of the Moon. ... For other moons in the solar system see natural satellite. ... For other moons in the solar system see natural satellite. ... Earth is the third planet from the Sun. ... Tidal locking makes one side of an astronomical body always face another, like the Moon facing the Earth. ... Earth is the third planet from the Sun. ...

The two hemispheres have a distinctly different appearance, with the near side covered in multiple, large maria. The far side has a battered, densely-cratered appearance with few mares. Only 2.5% of the surface of the far side is covered by maria, compared to 31.2% on the near side. The most likely explanation for this difference is that the crust of the Moon is 40 km thicker on the far side. Thus it was more difficult for molten materials to penetrate to the surface. A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... Look up lava, Aa, and pahoehoe in Wiktionary, the free dictionary. ...

The far side was sometimes referred to as the "Dark Side", due to the lack of human knowledge concerning that hemisphere. The word "Dark" in a cultural context was meant to express a lack of information, rather than the actual lighting conditions.

Exploration

Until the far side of the Moon was photographed by the Soviet probe Luna 3 in 1959, little was known about its properties. Librations of the Moon periodically allowed limited glimpses of features that are located near the lunar limb on the far side. These features, however, were seen from a low angle, hindering useful observation. (It proved difficult to distinguish a crater from a mountain range.) The remaining 41% of the surface on the far side remained unknown, and its properties were subject to much speculation. A sepia-tinted photograph of an English couple, taken in 1895. ... Soviet redirects here. ... Luna 3, an automatic interplanetary station of the Luna program, was the third spacecraft successfully launched to the Moon and the first to return images of the lunar far side. ... 1959 (MCMLIX) was a common year starting on Thursday of the Gregorian calendar. ... Although the Moon keeps the same side towards Earth, careful observations will reveal you can actually see 59% of the Moons surface. ...

An example of a far side feature that can be viewed through libration is the Mare Orientale, which is a prominent impact basin spanning almost 1,000 kilometers. Yet this wasn't even named as a feature until 1906, by Julius Franz in Der Mond. The true nature of the basin was discovered in the 1960s when rectified images were projected onto a globe. It was photographed in fine detail by Lunar Orbiter 4 in 1967. 1967 photograph made by NASAs Lunar Orbiter 4 Like a target ring bulls-eye, the lunar mare Mare Orientale (the eastern sea) is one of the most striking large scale lunar features. ... A kilometer (Commonwealth spelling: kilometre), symbol: km is a unit of length in the metric system equal to 1,000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... 1906 (MCMVI) was a common year starting on Monday (see link for calendar). ... Julius Heinrich Franz (1847–1913) was a German astronomer. ... The 1960s decade refers to the years from 1960 to 1969, inclusive. ... Lunar Orbiter 4 was designed to take advantage of the fact that the three previous Lunar Orbiters had completed the required needs for Apollo mapping and site selection. ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ...

As the far side was first viewed by Soviet space probes, the Russians selected many of the names for the prominent features. This action provoked some controversy, and so the International Astronomical Union later assumed the role of naming lunar features on this hemisphere. However, many of the names selected by the Soviets are still recognized. Soviet redirects here. ... Logo of the IAU The International Astronomical Union (French: Union astronomique internationale) unites national astronomical societies from around the world. ...

The far side was first observed directly by human eyes during the Apollo 8 mission in 1968. It has been seen by all crew members of the Apollo 10 through Apollo 17 missions since that time, and photographed by multiple lunar probes. Spacecraft passing behind the Moon were out of direct radio communication with the Earth, and had to wait until the orbit allowed transmission. During the Apollo missions, the main engine of the Service Module was fired when the vessel was behind the Moon, producing some tense moments in Mission Control before the craft reappeared. U.S. Space Shuttle astronaut Bruce McCandless II using a manned maneuvering unit (MMU) outside the Challenger in 1984. ... William A. Anders (born October 17, 1933) former National Aeronautics and Space Administration astronaut. ... Apollo 8 was the second manned mission of the Apollo space program, in which Commander Frank Borman, Command Module Pilot James Lovell and Lunar Module Pilot William Anders became the first humans to leave Earth orbit and to orbit around the Moon. ... Binomial name Homo sapiens Linnaeus, 1758 Subspecies Homo sapiens idaltu† Homo sapiens sapiens Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or thinking man) under the family Hominidae (the great apes). ... Apollo 8 was the second manned mission of the Apollo space program, in which Commander Frank Borman, Command Module Pilot James Lovell and Lunar Module Pilot William Anders became the first humans to leave Earth orbit and to orbit around the Moon. ... 1968 (MCMLXVIII) was a leap year starting on Monday (the link is to a full 1968 calendar). ... Apollo 10 was the fourth manned mission in the Apollo program, and the first (and only manned Saturn V) mission to launch from pad 39B. The mission included the second crew to orbit the Moon, and the test of the lunar module in lunar orbit. ... Apollo 17 was the eleventh manned space mission in the NASA Apollo program, and was the sixth and last mission to date to land on the Moon. ... An aerial view of the complete Johnson Space Center facility in Houston, Texas in 1989. ...

Potential

Because the far side of the Moon is shielded from radio transmissions from the Earth, it is considered a good location for placing radio telescopes for use by astronomers. Small, bowl-shaped craters provide a natural formation for a stationary telescope similar to Arecibo in Puerto Rico. For much larger-scale telescopes, the 100-kilometer diameter crater Daedalus is situated near the center of the far side, and the 3-km-high rim would help to block stray communications from orbiting satellites. Other potential candidates for a radio telescope include the Saha crater and the South Pole-Aitken Basin. The 64 metre radio telescope at Parkes Observatory, New South Wales, Australia In contrast to an ordinary telescope, which produces visible light images, a radio telescope sees radio waves emitted by radio sources, typically by means of a large parabolic (dish) antenna, or arrays of them. ... An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... 50 cm refracting telescope at Nice Observatory. ... Arecibo is a municipality in Puerto Rico named after the Taino Cacique Arasibo. ... A kilometer (Commonwealth spelling: kilometre), symbol: km is a unit of length in the metric system equal to 1,000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... Daedalus is a prominent crater located near the center of the far side of the Moon. ... Saha is a lunar impact crater on the Moons far side, behind the eastern limb as seen from the Earth. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ...

Before deploying radio telescopes to the far side, several problems must be overcome. The fine lunar dust can serve to contaminate equipment, vehicles, and space suits. The conducting materials used for the radio dishes must also be carefully shielded against the effects of solar flares. Finally the area about the telescopes must be protected against contamination by other radio sources. A Solar Flare, courtesy NASA A solar flare is a violent explosion in the Suns atmosphere with an energy equivalent to tens of millions of hydrogen bombs. ...

The L2 Lagrange point of the Earth-Moon system is located about 62,800 km above the far side. This has also been proposed as the location of a future radio telescope, performing a Lissajous ("Halo") orbit about the Lagrangian point. The Lagrangian points (IPA: ; also Lagrange point, L-point, or libration point), are the five positions in interplanetary space where a small object affected only by gravity can theoretically be stationary relative to two larger objects (such as a satellite with respect to the Earth and Moon). ... Lissajous figure on an Oscilloscope Lissajous figure in three dimensions In mathematics, a Lissajous curve (Lissajous figure or Bowditch curve) is the graph of the system of parametric equations which describes complex harmonic motion. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...

One of the NASA missions to the Moon under study would send a sample-return lander to the South Pole-Aitken basin, the location of a major impact event that created a formation nearly 2,400 kilometers across. The size of this impact has created a deep penetration into the lunar surface, and a sample returned from this site could be analyzed for information concerning the interior of the Moon. NASA logo Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ...

Because the near side is partly shielded from the solar wind by the Earth, the far side lunar mares are expected to have the highest concentration of Helium-3 on the surface of the Moon. This isotope is relatively rare on the Earth, but has good potential for use as a fuel in fusion reactors. Proponents of lunar settlement have cited presence of this material as a reason for development of a Moon base. The plasma in the solar wind meeting the heliopause For the British comic, see Solar Wind (comic). ... A map showing the location of Mare Imbrium The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... Helium-3 is a non-radioactive and light isotope of helium. ... Isotopes are forms of an element whose nuclei have the same atomic number - the number of protons in the nucleus - but different mass numbers because they contain different numbers of neutrons. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ...

Fictional references

• The novel Space by James Michener tells the fictional story of an Apollo 18 mission to the far side of the Moon. The novel was the source for a 1985 TV mini-series of the same name.
• The scientifically-questionable premise for the TV program Space: 1999 was the explosion of a nuclear waste dump on the far side of the Moon. This propelled the Moon out of Earth's orbit and deep into space.
• "Ideas Die Hard" (1957), a short story by Isaac Asimov, described an ill-fated trip to the dark side of the Moon. First appearing in Galaxy magazine, it was reprinted in The Winds of Change and Other Stories, ISBN 0-586-05743-9.
• In the anime show Grendizer, the Vega galactic empire has set up a base on the far side of the Moon from which they launch attacks on Earth.
• Pink Floyd had a seminal album titled Dark Side of the Moon, that, apart from the title and some lines in the songs "Brain Damage" and "Eclipse", had nothing to do with the Earth's physical moon. The use of the word lunatic in the album's lyrics, gains its stem from "luna" for moon, which denotes the traditional link made in folklore between madness and the phases of the moon.

Space is a novel by James A. Michener published in 1982. ... James Albert Michener (February 3, 1907? - October 16, 1997) was the American author of such books as Tales of the South Pacific (for which he won the Pulitzer Prize for Fiction in 1948), Hawaii, The Drifters, Centennial, The Source, The Fires of Spring, Chesapeake, Caribbean, Caravans, Alaska, Texas and Poland. ... Description Role: Earth and Lunar Orbit Crew: 3; CDR, CM pilot, LM pilot Dimensions Height: 36. ... This article is about the year. ... See also History of television. ... A miniseries (sometimes mini-series), in a serial storytelling medium, is a production which tells a story in a limited number of episodes. ... Wikimedia Commons has media related to: Science For the scientific journal named Science, see Science (journal). ... Left to right: Barbara Bain, Catherine Schell and Martin Landau from Space:1999s second season. ... Nuclear materail consists of materials used in nuclear systems. ... 1957 (MCMLVII) was a common year starting on Tuesday of the Gregorian calendar. ... Isaac Asimov, photographed by Jay Kay Klein Dr. Isaac Asimov (c. ... The Puppet Masters by Robert A. Heinlein in Galaxy, Sept. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Pink Floyd (formed in 1965 in Cambridge, England) is an English rock band, noted for progressive compositions, philosophic lyrics, sonic experimentation, cover art, and elaborate live shows. ... This article is about the Pink Floyd album. ... Brain Damage is a song by the British progressive rock band Pink Floyd. ... Eclipse is a song by the British progressive rock band Pink Floyd. ... A lunatic (colloquially: loony) is commonly used term for a person who is mentally ill, dangerous, foolish or unpredictable, a condition once called lunacy. ... Folklore is the body of verbal expressive culture, including tales, legends, oral history, proverbs, jokes, popular beliefs current among a particular population, comprising the oral tradition of that culture, subculture, or group. ... The lunar effect is the supposed influence of the moon, and its various phases, on human behaviour. ...

External links

• Northwest Africa 482, only meteorite believed to have originated from the far side of the Moon

• Prospecting for Helium-3 on the Moon