Moon exploration
The space 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. Until then, the only means available exploration was observation from Earth. The invention of the optical telescope marked the first leap in quality in lunar observations. Galileo Galilei is generally recognized as the first person to use a telescope for astronomical purposes; having made his own telescope in 1609, mountains and craters on the lunar surface were some of his first observations with it.
NASA's Apollo program was the only one to land humans on the Moon, which it did six times. The first landing took place in 1969, when two Apollo 11 astronauts set up scientific instruments and returned lunar samples to Earth.
The first unmanned landing on the far side of the Moon was made by the Chinese Chang'e 4 spacecraft in early 2019, successfully deploying the Yutu-2 lunar rover.
Background
The ancient Greek philosopher Anaxagoras (d. 428 BC) reasoned that the Sun and Moon were giant spherical rocks and that the latter reflected light from the former. His non-religious view of the heavens was one of the causes of his imprisonment and subsequent exile. In his book On the Face in the Orb of the Moon, Plutarch suggested that the Moon had deep recesses to which that the sunlight did not reach and that the spots are nothing more than the shadows of rivers or deep abysses. He also contemplated the possibility that the Moon was inhabited. Aristarchus went one step further and calculated the distance to Earth, along with its size, getting a value of 20 times the Earth's radius for the distance (the actual value is 60; the Earth's radius has been known roughly since Eratosthenes)..
Although the Chinese of the Han dynasty (202 BC-AD 202) believed that the moon was an energy comparable to qì, their theory of "radiant influence" recognized that moonlight was not it was more than a reflection of the Sun (mentioned above by Anaxagoras). This was supported by mainstream thinkers, such as Jing Fang, who pointed to the sphericity of the Moon. Shen Kuo (1031-1095), of the Song dynasty (960-1279), created an allegory in which he equated the waxing and waning of the Moon with a round ball of reflective silver that, when sprinkled with white powder and viewed From the side, it would look like a crescent.
Around 499, the Indian astronomer Aryabhata mentioned in his Aryabhatiya that reflected sunlight is what makes the Moon shine.
Habash al-Hasib al-Marwazi, a Persian astronomer, made several observations at the Al-Shammisiyyah observatory in Baghdad between AD 825 and 835. C. From these observations, he estimated the diameter of the Moon at 3,037 km (equivalent to 1,519 km radius) and its distance from Earth at 346,345 km. In the 11th century, the Islamic physicist Alhacen investigated moonlight through a series of experiments and observations, concluding that it was a combination of the Moon's own light and the Moon's ability to absorb and emit sunlight.
In the Middle Ages, before the invention of the telescope, an increasing number of people began to recognize that the Moon was a sphere, although many believed it to be "perfectly smooth". In 1609, Galileo Galilei drew one of the first telescopic drawings of the Moon in his book Sidereus nuncius and observed that it was not smooth, but had mountains and craters. Later, in the 17th century, Giovanni Battista Riccioli and Francesco Maria Grimaldi drew a map of the Moon and gave many craters the names they still have today. On maps, the dark parts of the Moon's surface were called maria (singular mare) or mares, and the light parts were called terrae or continents.
Thomas Harriot, like Galilei, drew the first telescopic representation of the Moon and observed it for several years. His drawings, however, remained unpublished. The first map of the Moon was made by the Belgian cosmographer and astronomer Michael Florent van Langren in 1645. Two years later, Johannes Hevelius published a much more influential work. In 1647 Hevelius published the Selenographia, the first treatise entirely devoted to the Moon. The Hevelius nomenclature, although used in Protestant countries until the 17th century, was superseded by the system published in 1651 by the Jesuit astronomer Giovanni Battista Riccioli, who gave the name of the large spots with the naked eye as seas and the telescopic spots (now called craters) that of philosophers and astronomers.
In 1753, the Croatian Jesuit and astronomer Ruđer Bošković discovered the absence of an atmosphere on the Moon. In 1824, Franz von Gruithuisen explained the formation of craters as a result of falling meteorites.
The possibility that the Moon contains vegetation and is inhabited by selenites was seriously considered by leading astronomers even in the early decades of the century XIX. In 1834-1836, Wilhelm Beer and Johann Heinrich Mädler published their Mappa Selenographica, in four volumes, and the book Der Mond, in 1837, which firmly established the conclusion that the Moon has no appreciable bodies of water or atmosphere.
Space Age
Cold War
The "space race" and "moon race" between the Soviet Union and the United States, inspired by the Cold War, accelerated with a focus on the Moon. This included many important scientific firsts, such as the first photographs of the far side of the Moon, in 1959, by the Soviet Union, and culminating in the landing of the first humans on the Moon in 1969, widely regarded around the world. as one of the seminal events of the 20th century, and indeed of human history in general.
The first man-made object to fly over the Moon was the uncrewed Soviet Luna 1 probe on January 4, 1959, and it was the first probe to reach a heliocentric orbit around the Sun. Few knew that Luna 1 was designed to impact the surface of the Moon.
The first probe to impact the surface of the Moon was the Soviet Luna 2 probe, which made a forced landing on September 14, 1959, at 21:02:24 UTC. The far side of the Moon was first photographed on October 7, 1959 by the Soviet Luna 3 probe. Although imprecise by today's standards, the photos showed that the far side of the Moon was almost completely devoid of maria.
The first American probe to fly over the Moon was Pioneer 4, on March 4, 1959, shortly after Luna 1. But it was the only success of the 8 American probes that attempted to land on the Moon for the first time.
It would be 3 more years and six failed Ranger missions before Ranger 7 returned close-up photos of the lunar surface before impacting with it in July 1964. A series of problems with the launch vehicles, the ground and spacecraft electronics plagued the Ranger program and early sounding missions in general. These lessons were fed into Mariner 2, the only American space probe to succeed after Kennedy's famous speech to Congress and before Kennedy's death in November 1963. America's success rates improved greatly after the Ranger. 7.
In 1966, the USSR made the first soft landings and took the first photographs of the lunar surface during the Luna 9 and Luna 13 missions.
The United States followed Ranger with the Surveyor program, which sent seven robotic spacecraft to the surface of the Moon. Five of the seven spacecraft landed successfully, investigating whether the regolith (dust) was shallow enough for astronauts to be on the Moon.
On December 24, 1968, the Apollo 8 crew, Frank Borman, James Lovell, and William Anders, became the first humans to enter lunar orbit and see the far side of the Moon in person. Humans first landed on the Moon on July 20, 1969. The first human to walk on the lunar surface was Neil Armstrong, commander of the US Apollo 11 mission.
The first lunar robot to land on the Moon was the Soviet spacecraft Lunokhod 1 on November 17, 1970, as part of the Lunokhod program. To date, the last human being to set foot on the Moon was Eugene Cernan, who, as part of the Apollo 17 mission, walked on the Moon in December 1972.
Moon rock samples were brought to Earth by three Luna missions (Luna 16, 20 and 24) and the Apollo 11 through 17 missions (except Apollo 13, which aborted its planned moon landing). Luna 24, in 1976, was the last lunar mission by the Soviet Union or the United States until Clementine in 1994. Attention focused on probes to other planets, space stations, and the shuttle program.
Before the race to the Moon, the United States had previous projects for scientific and military lunar bases: Project Lunex and Project Horizon. In addition to manned moon landings, abandoned Soviet lunar programs included the construction of a "Zvezda" multipurpose lunar base, the first detailed project, with developed mock-ups of expedition vehicles and surface modules.
After 1990
In 1990, Japan visited the Moon with the Hiten spacecraft, becoming the third country to put an object into orbit around the Moon. The spacecraft launched the Hagoromo probe into lunar orbit, but the transmitter failed, preventing further use of the spacecraft for scientific purposes. In September 2007, Japan launched the SELENE spacecraft, with the goals of "obtaining scientific data on lunar origin and evolution and developing technology for future lunar exploration", according to the official JAXA website.
The European Space Agency launched a small, low-cost lunar orbital probe called SMART 1 on September 27, 2003. The primary purpose of SMART 1 was to take three-dimensional X-ray and infrared images of the lunar surface. SMART 1 entered lunar orbit on November 15, 2004, and continued to make observations until September 3, 2006, when it intentionally crashed into the lunar surface to study the impact plume.
China has launched the China Lunar Exploration Program to explore the Moon and is investigating the prospect of lunar mining, specifically looking for the helium-3 isotope to use as a power source on Earth. China launched the Chang'e 1 robotic lunar orbiter on October 24, 2007. Originally scheduled for a one-year mission, the Chang'e 1 mission was very successful and was eventually extended for another four months. On March 1, 2009, Chang'e 1 intentionally impacted the lunar surface completing the 16-month mission. On October 1, 2010, China launched the Chang'e 2 lunar orbiter. China landed the Chang'e 3 rover on the Moon on December 14, 2013, becoming the third country to do so. 39;e 3 is the first spacecraft to gently land on the lunar surface since Luna 24 in 1976. Since the Chang'e 3 mission was a success, the Chang'e 4 backup lander was reused for the new mission objectives. China launched the Chang'e 4 mission to the far side of the Moon on December 7, 2018. On January 3, 2019, Chang'e 4 landed on the far side of the Moon. Chang'e 4 deployed the Yutu-2 lunar rover, which subsequently became the current distance record holder for travel on the lunar surface. Among other discoveries, Yutu-2 discovered that dust in some places on the far side of the Moon is up to 12 meters deep.
India's national space agency, ISRO, launched Chandrayaan-1, an uncrewed lunar orbiter, on October 22, 2008. The lunar probe was to orbit the Moon for two years, with the scientific goals of preparing a three-dimensional atlas of the near and far sides of the Moon and to perform chemical and mineralogical mapping of the lunar surface. The orbiter released the Lunar Impact Probe which impacted the Moon at 15:04 GMT on November 14, 2008, making India the fourth country to reach the lunar surface. One of Chandrayaan's many achievements was the discovery of the widespread presence of water molecules in lunar soil. This mission was followed by Chandrayaan-2, which launched on July 22, 2019 and entered lunar orbit on August 20, 2019. Chandrayaan-2 was also carrying India's first lander and rover, but these were they crashed.
The Ballistic Missile Defense Organization and NASA launched the Clementine mission in 1994, and Lunar Prospector in 1998. NASA launched the Lunar Reconnaissance Orbiter on June 18, 2009, which has collected images of the surface of Moon. It also carried the Lunar Crater Detection and Observation Satellite (LCROSS), which investigated the possible existence of water in Cabeus crater. GRAIL is another mission, launched in 2011.
The first commercial mission to the Moon was carried out by the Manfred Memorial Moon Mission (4M), led by LuxSpace, a subsidiary of the German company OHB AG. The mission was launched on October 23, 2014 with the Chinese Chang'e 5-T1 test spacecraft, attached to the upper stage of a Long March 3C/G2 rocket. The 4M spacecraft performed a flyby of the Moon. on a night on October 28, 2014, after which it entered an elliptical Earth orbit, exceeding its designed lifetime by four times.
The Beresheet lander, operated by Israel Aerospace Industries and SpaceIL, impacted the Moon on April 11, 2019 after a failed landing attempt.
China planned to carry out a sample return mission with its Chang'e 5 spacecraft in 2017, but that mission was postponed due to the failure of the Long March 5 launch vehicle. However, after the Long March 5 rocket to fly successfully again at the end of December 2019, China set its Chang'e 5 sample return mission for the end of 2020. China completed this mission on December 16, 2020 with the return of approximately 2 kilograms of lunar sample.
In 2022 South Korea, within the first phase of its lunar exploration program, launched the Korea Pathfinder Lunar Orbiter (KPLO), officially called Danuri, a lunar orbiter whose objectives are the development of technologies for lunar exploration; identify potential landing sites for future missions; and to inspect lunar resources such as water ice, uranium, helium-3, silicon, and aluminum. The probe was launched on August 4 to enter lunar orbit on December 16, 2022.