Exploration of the Moon
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The physical exploration of the Moon began when Luna 2, a space probe launched by the Soviet Union, impacted the surface of the Moon on September 14, 1959. Prior to that the only available means of exploration had been observation. The invention of the optical telescope brought about the first leap in the quality of lunar observations. Galileo Galilei is generally credited as the first person to use a telescope for astronomical purposes; having made his own telescope in 1609, the mountains and craters on the lunar surface were among his first observations using it.
In 1969, Project Apollo first successfully landed people on the Moon. They placed scientific experiments there and returned rocks and data that suggested the Moon is of a similar composition to the Earth.
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[edit] Early history
- Further information: Selenography
In the philosophy of Aristotle, the heavens, starting at the Moon, were the realm of perfection, the sublunary region was the realm of change and corruption, and any resemblance between these regions was strictly ruled out. Aristotle himself suggested that the Moon partook perhaps of some contamination from the realm of corruption.[1] In his little book On the Face in the Moon's Orb, Plutarch expressed rather different views on the relationship between the Moon and Earth. He suggested that the Moon had deep recesses in which the light of the Sun did not reach and that the spots are nothing but the shadows of rivers or deep chasms. He also entertained the possibility that the Moon was inhabited. It had been suggested already in antiquity that the Moon was a perfect mirror and that its markings were reflections of earthly features, but this explanation was easily dismissed because the face of the Moon never changes as it moves about the Earth.[1] The explanation that finally became standard was that there were variations of "density" in the Moon that caused this otherwise perfectly spherical body to appear the way it does.[1] The perfection of the Moon, and therefore the heavens, was thus preserved.
The medieval followers of Aristotle, in the Islamic world and then in Christian Europe, tried to make sense of the lunar spots in Aristotelian terms.[1] Thomas Harriot, as well as Galilei, drew the first telescopic representation of the Moon and observed it for several years. His drawings, however, remained unpublished.[1] The first map of the Moon was made by the Belgian cosmographer and astronomer Michael Florent van Langren in 1645.[1] Two years later a much more influential effort was published by Johannes Hevelius. In 1647 Hevelius published Selenographia, the first treatise entirely devoted to the Moon. Hevelius's nomenclature, although used in Protestant countries until the eighteenth century, was replaced by the system published in 1651 by the Jesuit astronomer Giovanni Battista Riccioli, who gave the large naked-eye spots the names of seas and the telescopic spots (now called craters) the name of philosophers and astronomers.[1] In 1753 Croatian astronomer Roger Joseph Boscovich discovered the absence of atmosphere on the Moon. In 1824 Franz von Gruithuisen explained the formation of craters as a result of meteorite strikes.[2]
[edit] Space race
The Cold War-inspired space race between the Soviet Union and the United States of America accelerated with a focus on the Moon. This included many scientifically important firsts, such as the first photographs of the until then unseen far side of the moon in 1959 by the Soviet Union, and culminated with the landing of the first humans on the moon in 1969, widely seen around the world as one of the pivotal events of the 20th century, and indeed of human history in general.
The first man-made object to reach the Moon was the unmanned Soviet probe Luna 2, which made a hard landing on September 14, 1959, at 21:02:24 Z. The far side of the Moon was first photographed on October 7, 1959 by the Soviet probe Luna 3. In an effort to compete with these Soviet successes, U.S. President John F. Kennedy proposed the national goal of landing a man on the Moon. Speaking to a Joint Session of Congress on May 25, 1961, he said
"First, I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space."[3]
The Soviets nonetheless remained in the lead for some time. Luna 9 was the first probe to soft land on the Moon and transmit pictures from the Lunar surface on February 3, 1966. It was proven that a lunar lander would not sink into a thick layer of dust, as had been feared. The first artificial satellite of the Moon was the Soviet probe Luna 10 (launched March 31, 1966). One of the main impediments to human exploration of the Moon was development of adequate heat shield technology to permit atmospheric re-entry without completely burning up a manned spacecraft. The U.S. gained early supremacy in this field through NASA research in thermogravimetric experiments in hypersonic wind tunnels.
On December 24, 1968, the crew of Apollo 8, Frank Borman, James Lovell, and William Anders became the first human beings to see the far side of the Moon with their own eyes (as opposed to seeing it on a photograph). Humans first landed on the Moon on July 20, 1969. The first man to walk on the lunar surface was Neil Armstrong, commander of the U.S. mission Apollo 11. The first robot lunar rover to land on the Moon was the Soviet vessel Lunokhod 1 on November 17, 1970 as part of the Lunokhod program. The last man to stand on the Moon was Eugene Cernan, who as part of the mission Apollo 17 walked on the Moon in December 1972. See also: A full list of lunar Apollo astronauts.
Moon rock samples were brought back to Earth by three Luna missions (Luna 16, 20, and 24) and the Apollo missions 11 through 17 (excepting Apollo 13, which aborted its planned lunar landing).
From the mid-1960's to the mid-1970's there were 65 moon landings (with 10 in 1971 alone), but after Luna 24 in 1976 they suddenly stopped. The Soviet Union started focusing on Venus and space stations and the U.S. on Mars and beyond.
[edit] Recent exploration
In 1990 Japan visited the moon with the Hiten spacecraft, becoming the third country to orbit the moon. The spacecraft released the Hagormo probe into lunar orbit, but the transmitter failed, thereby preventing further scientific use of the mission. In September 2007, the SELENE spacecraft was launched, with the objectives "to obtain scientific data of the lunar origin and evolution and to develop the technology for the future lunar exploration", according to the JAXA official website.[4]
NASA launched the Clementine mission in 1994, and Lunar Prospector in 1998.
In 1998, HGS-1, a commercial satellite from Hong Kong, China, performed two flybys of the moon in order to change orbital inclination.
The European Space Agency launched a small, low-cost lunar orbital probe called SMART 1 on September 27, 2003. SMART 1's primary goal was to take three-dimensional X-ray and infrared imagery of the lunar surface. SMART 1 entered lunar orbit on November 15, 2004 and continued to make observations until September 3, 2006, when it was intentionally crashed into the lunar surface in order to study the impact plume.[5]
The People's Republic of China has begun the Chang'e program for exploring the Moon and is investigating the prospect of lunar mining, specifically looking for the isotope helium-3 for use as an energy source on Earth.[6] China launched the Chang'e 1 robotic lunar orbiter on 2007-10-24.
[edit] Future plans
- See also: List of future lunar missions
On 2004-01-14, US President George W. Bush announced the Vision for Space Exploration, a plan leading to new manned lunar missions by 2020. NASA's plan to accomplish that goal was announced on March 19, 2005,[7] and was promptly dubbed "Apollo 2.0" by critics. A preliminary unmanned mission, the Lunar Reconnaissance Orbiter, is scheduled for launch in 2008. LRO will take high resolution imagery of the moon's surface and will carry the Lunar Crater Observation and Sensing Satellite (LCROSS), which will investigate the possible existence of water in Shackleton crater.
China plans to land a rover on the moon in 2012, and to conduct a sample return mission in 2017. China has entered into an agreement to work with Russia to eventually land astronauts on the moon before 2020.[8]
Japan has rescheduled LUNAR-A possibly before 2010.[9] Japanese Space Agency (JAXA) plans a manned lunar landing around 2020 that would lead to a manned lunar base by 2030; however, there is no budget yet for this project.[10]
India expects to launch Chandrayaan, an unmanned lunar orbiter, by April 2008. The Indian Space Research Organisation (ISRO) also plans to undertake a totally indigenous manned space exploration in the next decade by planning to send a person to space by 2014 and to have a person walk on the moon by 2020.[11]
Russia also announced to resume its previously frozen project Luna-Glob, an unmanned lander and orbiter, which is slated to launch in 2012.[12]
Germany also announced in March 2007 that it will launch a national lunar orbiter, LEO in 2012.[13]
In August 2007, NASA stated that all future missions and explorations of the moon will be done entirely using the metric system. This was done to improve cooperation with space agencies of other countries which already use the metric system.[14]
The European Space Agency has also announced its intention to send a manned mission to the Moon, as part of the Aurora programme.
On September 13, 2007, the X Prize Foundation, in concert with Google, Inc., announced the Google Lunar X Prize. This contest requires competitors "to land a privately funded robotic rover on the Moon that is capable of completing several mission objectives, including roaming the lunar surface for at least 500 meters and sending video, images and data back to the Earth."[15]
[edit] See also
- List of artificial objects on the Moon
- Moon landing
- Project Apollo
- Robotic exploration of the Moon
- Helium-3
[edit] References
- ^ a b c d e f g The Galileo Project. Retrieved on 2007-09-14.
- ^ (1998) Энциклопедия для детей (астрономия). Москва: Аванта+. ISBN 5-89501-016-4.
- ^ Special Message to the Congress on Urgent National Needs Page 4 - John F. Kennedy Presidential Library & Museum
- ^ Kaguya (SELENE). JAXA. Retrieved on 2007-06-25.
- ^ ESA's Moon mission ends successfully. ESA (4 September 2006). Retrieved on 2006-09-03.
- ^ David, Leonard (04 March 2003). China Outlines its Lunar Ambitions. Space.com. Retrieved on 2006-03-20.
- ^ How We'll Get Back to the Moon. NASA. Retrieved on 2006-03-20.
- ^ AP (11 September 2006). Russia-China plan for moon mission. CNN.com. Retrieved on 2006-09-16.
- ^ Mission Schedule. Institute of Space and Astronautical Science. Japan Aerospace Exploration Agency (2007). Retrieved on 2007-09-15.
- ^ Staff Writers (August 3, 2006). Japan Plans Moon Base By 2030. Moon Daily. SpaceDaily. Retrieved on 2006-11-17.
- ^ Staff Writers (November 4, 2004). Competition heating up for Moon exploration. IOL. Retrieved on 2008-01-25.
- ^ Covault, Craig (June 4, 2006). Russia Plans Ambitious Robotic Lunar Mission.
- ^ news, Spiegel (February 28, 2007). Germany plans own moon mission.
- ^ NASA - Metric Moon
- ^ Google Sponsors Lunar X PRIZE to Create a Space Race for a New Generation. X PRIZE Foundation. Retrieved on 2007-09-13.
[edit] External links
- Lunar mission timeline - NASA
- Recent Lunar missions - NASA
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