The far side of the Moon, sometimes figuratively known as the dark side of the Moon , is the Moon's hemisphere that is always facing away from Earth. The field on the far side is rough, with many impact craters and relatively few maria flat months. It has one of the largest craters in the Solar System, the Arctic-Aitken basin. Although both sides of the Moon experience two weeks of sunlight followed by two weeks of the night, the far side is sometimes called the "dark side of the Moon," with "dark" meaning "invisible" rather than lacking light.
About 18% of the far side is sometimes seen from Earth due to libration. The remaining 82% remained unobserved until 1959, when the Soviet Luna 3 spacecraft photographed it. The Soviet Academy of Sciences published the first atlas from the far side in 1960. In 1968, Apollo 8 mission astronauts were the first humans to see this region directly as they orbit the Moon. Until now, no human has ever stood on the surface of the far side of the Moon.
Astronomers suggest installing large radio telescopes on the far side, where the Moon will protect from possible radio interference from Earth.
Video Far side of the Moon
Definisi
The tidal forces of the Earth have slowed the rotation of the Moon to the point where the same side always faces Earth - a phenomenon called tidal locking. Other faces, most of which are never seen from Earth, are therefore called "the far side of the Moon". Over time some parts of the far side can be seen due to libration. In total 59 percent of the Moon's surface is visible from the Earth at one time or another. Useful observations of the far side sections The moon that is sometimes seen from Earth is difficult because of the low viewpoint of the Earth (they can not be observed "full on").
The idiomatic phrase "dark side of the Moon" does not refer to "dark" as in the absence of light, but "dark" as it is unknown: until humans can send spacecraft around the Moon, this area is never seen. While many misunderstand this to think that the "dark side" receives little or no sunlight, in fact, both the near and far side accept (average) the amount of light almost equal directly from the Sun. However, the near side also receives reflected sunlight from Earth, known as earth's light. The sun does not reach the far side area that can not be seen from Earth. Only during the full moon (as seen from Earth) is the whole side of the dark Moon. The word "dark" has been extended to also refer to the fact that communications with the spacecraft can be blocked while on the far side of the Moon, during the Apollo space mission for example.
Maps Far side of the Moon
Differences
The two hemispheres have distinctly different apparitions, with the closely enclosed side of many, the great maria (Latin for 'oceans', since the early astronomers mistook the plains for the lunar waters). The far side has a dense, crater sight with little maria. Only 1% of the surface of the far side is covered by maria, compared with 31.2% on the near side. One commonly accepted explanation for this difference is associated with higher concentrations of heat-generating elements in the near hemisphere, as shown by the geochemical maps obtained from the Lunar Prospector gamma ray spectrometer. While other factors such as surface elevation and thickness of the crust can also affect where the basal erupts, this does not explain why the South-Aitken farside basin (which contains the Moon's lowest elevation and has a thin crust) is not as active as volcanic. Oceanus Procellarum on the near side.
It has also been proposed that the difference between the two hemispheres may be caused by collisions with smaller companion moon which also comes from Theia collision. In this model, the impact leads to additional stacks rather than craters, contributing broad hemispheric layers and thicknesses that may be consistent with the dimensions of the farside plateau.
The far side has a more visible crater. This is thought to be the result of the lava flow effect of the moon, which obscures and obscures the crater, not the shielding effect of the Earth. NASA calculates that the Earth obscures only about 4 degrees square of 41,000 degree square sky as seen from the Moon. "It makes the Earth negligible as a shield for the Moon... The probability that every side of the Moon has received the same amount of impact, but the lava reapplying produces fewer craters visible on the near side than the far side, though both sides has received the same amount of impact. "
New research shows that the reason the Moon side facing Earth has fewer crater impacts is the heat from Earth at the time the Moon is formed. The moon's crust consists mainly of plagioclase formed when aluminum and calcium are condensed and combined with silicates in the mantle. The distant cold sides are condensing these elements faster and form thicker crusts; The meteoroid impact on the near side occasionally penetrates the thinner crust here and releases the basaltic lava that creates maria, but rarely does it on the far side.
Exploration
Until the late 1950s, little was known about the far side of the Moon. Librations of the Moon periodically allow a limited glimpse of features near the moon members on the far side. These features, however, are seen from a low angle, obstructing useful observations. (Proven difficult to distinguish the crater from the mountains). The remaining 82% of the surface on the far side is still unknown, and its properties are subject to much speculation.
An example of a remote side feature that can be seen through libration is Mare Orientale, which is a major impact basin stretching nearly 1,000 kilometers (600 mi), but this is not even referred to as a feature until 1906, by Julius Franz at Der Mond. i>. The original nature of the basin was discovered in the 1960s when an improved image was projected onto the world. The basin was photographed in fine detail by Lunar Orbiter 4 in 1967.
Before space exploration begins, astronomers do not expect that the far side will be different from the visible side to Earth. On October 7, 1959, Soviet investigation Luna 3 took the first photographs of the far side of the moon, eighteen of them solvable, covering a third of the invisible surface of Earth. The images were analyzed, and the first atlas from the far side of the Moon was published by the USSR Academy of Sciences on November 6, 1960. It included a catalog of 500 differentiated landscape features. A year later the first world ball (scale 1:13 600 000) containing the invisible moon feature from Earth was released in the Soviet Union, based on images from Luna 3. On July 20, 1965 another Soviet inquiry, Zond 3, sent 25 very high quality pictures both from the far side of the lunar, with a much better resolution than Luna 3. In particular, they reveal a crater chain, hundreds of kilometers long, but, unexpectedly, there is no mare plain as seen from Earth with the naked eye. In 1967 the second part of the "Atlas of the Side of the Moon" was published in Moscow, based on data from Zond 3, with the current catalog including 4,000 newly discovered features of the far-flung landscape of the moon. In the same year, the first "Full Moon Map" (scale 1: 5 000 000) and complete updated globe (1:10 000 000 scale), which featured 95 percent of the surface of the moon, was released in the Soviet Union.
Since many landscape features that stand out from the far side are found by Soviet spaceships, Soviet scientists pick names for them. This caused some controversy, and the International Astronomical Union, left many of the names intact, then took on the role of naming the moon features in this hemisphere.
On April 26, 1962, NASA Ranger 4 spacecraft became the first spacecraft to impact on the far side of the Moon, despite failing to restore any scientific data prior to the collision.
The first comprehensive and detailed long-range mapping survey was conducted by an American unmanned Lunar Orbiter program launched by NASA from 1966 to 1967. Much of the coverage of the far side was provided by the final probe in the Lunar Orbiter series 5.
The far side was first seen directly by the human eye during the Apollo 8 mission in 1968. Astronaut William Anders described the view:
The back looks like a pile of sand my kids played for some time. It's all pulsating, there's no definition, just a lot of bumps and holes.
It has been seen by all Apollo 8 and Apollo 10 crew members via the Apollo 17 mission since then, and photographed by some probes of the moon. The spacecraft passing behind the Moon is outside direct radio communications with Earth, and must wait until its orbit transmission is permitted. During the Apollo mission, the Service Module's main engine was fired when the ship was behind the Moon, producing some tense moments in Mission Control before the plane reappeared.
Geologist-astronaut Harrison Schmitt, who became the last person to step onto the Moon, has aggressively lobbied for his landing site to be on the far side of the Moon, targeting the lava crater lava, Tsiolkovskiy. Schmitt's ambitious proposition includes a special communications satellite based on existing TIROS satellites to be launched into Farquhar-Lissajous halo orbit around the L2 point so as to maintain a line-of-sight contact with astronauts during the decline in electricity and moon surface operations. The NASA administrator rejected this plan on the basis of additional risk and lack of funding.
The China National Space Administration is planning for Chang'e 4 mission to reach its first landing on the far side of the moon by the end of 2018. The landing will be equipped with a low frequency radio frequency spectrograph and geological research tool.
Potential
Because the Moon side is far protected from radio transmissions from Earth, it is considered a good location to place radio telescopes for use by astronomers. The bowl-shaped crater provides a natural formation for stationary telescopes similar to Arecibo in Puerto Rico. For larger-scale telescopes, the 100-km (62 mi) diameter crater Daedalus is located near the center of the far side, and 3 km (2 mi) - high edges will help block lost communication from orbiting satellites. Another potential candidate for a radio telescope is the Saha crater.
Before spreading the radio telescope to the far side, some problems must be solved. Smooth lunar dust can contaminate equipment, vehicles, and spaceship. Conductor materials used for radio antennas should also be carefully guarded against the effects of solar flares. Finally the area around the telescope must be protected from contamination by other radio sources.
The Lagrange point of the Earth-Moon system lies about 62,800 km (39,000 mi) above the far side, which has also been proposed as a location for future radio telescopes that will perform the Lissajous orbit about the Lagrangian point.
One of the NASA missions to the Moon under investigation will send a landing sample to the Arctic-Aitken basin, the site of major impact events that created the formation of nearly 2,400 kilometers (1,491 mi). The strength of this impact has created deep penetration into the lunar surface, and return samples from this site can be analyzed for information on the inside of the Moon.
Because the near side is partially sheltered from the solar wind by the Earth, the far-flung maria is expected to have the highest helium-3 concentrations on the Moon's surface. This isotope is relatively rare on Earth, but has good potential for use as a fuel in fusion reactors. Supporters of the moon settlement have mentioned the existence of this material as an excuse to develop the Moon base.
Suspected UFO sightings and conspiracy
Some conspiracy theorists, notably Milton William Cooper, alleged that some Apollo astronauts had seen UFOs on the far side of the Moon but were told to keep silent about them. Some people allegedly reported seeing an alien base (code named "Luna") and even encountered aliens who told them to distance themselves from the Moon. Some photos circulating on the Internet are meant to show the great "castle" on the Moon. NASA states that this claim is a hoax.
The late Secretary of Defense Robert McNamara stated that unidentified officials ("Chiefs") in the Pentagon opposed the Nuclear Test Ban Treaty between the United States and the Soviet Union, arguing that the Soviets would continue nuclear weapons testing away from the Moon, away from observations American observers. McNamara considers this premise "... absurd" and that "[they] are [out of [their] minds", but he believes that it is an example of the state of mind of several Pentagon officials during the Cold War. Ironically, it was later revealed that the Pentagon had their own plans to blow up nuclear weapons on the Moon as part of the A119 Trial Project. This project is made not only to help answer some of the mysteries in planetary astronomy and astrogeology, but also as a show of force intended to boost domestic confidence in the ability of the US astro, a boost that is deemed necessary after the Soviet Union took the lead in the Space Race and which was perceived by some people to work on similar projects.
See also
- Moon Geology
- Hypothesis of the giant impact
- south pole of Lunar
- Near the Moon side
- Patsaev (crater)
References
External links
- Lunar and Planetary Institute: Exploring the Moon
- [2]
- Lunar and Planetary Institute: Lunar Atlases
- Ralph Aeschliman Planetary Cartography and Graphs: Lunar Maps
- Northwest Africa 482, only meteorites believed to originate from the far side of the Moon
- The moon article on Discoveries of Planet Science Research
- Merrifield, Michael. "Far Side of the Moon". Sixty Symbols . Brady Haran for the University of Nottingham.
Source of the article : Wikipedia
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