The physical exploration of the Moon began when Luna 2, a space probe launched by the Soviet Union, made a deliberate impact on the surface of the Moon on 14 September, 1959. Prior to that the only available means of lunar exploration had been observations from Earth. 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.
Human exploration of the Moon since Luna 2 has consisted of both crewed and uncrewed missions. NASA's Apollo program has been the only program to successfully land humans on the Moon, which it did six times on the near side in the late 20th century. The first human landing took place in 1969, when the Apollo 11 astronauts Buzz Aldrin and Neil Armstrong touched down on the surface in the region of Mare Tranquillitatis, leaving scientific instruments upon the mission's completion and returning lunar samples to Earth. All lunar missions had taken place on the lunar near side until the first soft landing on the far side of the Moon was made by the CNSA robotic spacecraft Chang'e 4 in early 2019, which successfully deployed the Yutu-2 robotic lunar rover. On 25 June 2024, CNSA's Chang'e 6 conducted the first lunar sample return from the far side of the Moon.
The goals of lunar exploration across all major space agencies focus on the continued survey of the lunar surface through lunar missions in preparation for the eventual establishment of permanent human outposts.
Pre-telescopic
It is believed by some that the oldest cave paintings from up to 40,000 BP of bulls and geometric shapes, or 20–30,000-year-old tally sticks were used to observe the phases of the Moon, keeping time using the waxing and waning of the Moon's phases. Aspects of the Moon were identified and aggregated in lunar deities from prehistoric times and were eventually documented and put into symbols from the very first instances of writing in the 4th millennium BC. One of the earliest known possible depictions of the Moon is a 3,000 BCE rock carving Orthostat 47 at Knowth, Ireland. The crescent depicting the Moon, as with the lunar deity Nanna/Sin, has been found from the 3rd millennium BCE.
The oldest named astronomer and poet, Enheduanna, Akkadian high priestess to the lunar deity Nanna/Sin and princess, daughter of Sargon the Great ( – BCE), had the Moon tracked in her chambers. The oldest found and identified depiction of the Moon in an astronomical relation to other astronomical features is the Nebra sky disc from , depicting features like the Pleiades next to the Moon.
The ancient Greek philosopher Anaxagoras, whose non-religious view of the heavens was one cause for his imprisonment and eventual exile, reasoned that the Sun and Moon were both giant spherical rocks and that the latter reflected the light of the former. Plutarch, in his book On the Face in the Moon's Orb, 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. Aristarchus attempted to compute the Moon's size and distance from Earth, although his estimated distance of 20 times Earth's radius (which had been accurately determined by his contemporary Eratosthenes) proved to be about a third the actual average distance.
Chinese philosophers of the Han dynasty believed the Moon to be energy equated to qi but recognized that the light of the Moon was a reflection of the Sun. Mathematician and astrologer Jing Fang noted the sphericity of the Moon. Shen Kuo of the Song dynasty created an allegory equating the waxing and waning of the Moon to a round ball of reflective silver that, when doused with white powder and viewed from the side, would appear to be a crescent.
Indian astronomer Aryabhata stated in his fifth-century text Aryabhatiya that reflected sunlight is what causes the Moon to shine.Hayashi (2008), Aryabhata I.
Persian astronomer Habash al-Hasib al-Marwazi conducted various observations at the Al-Shammisiyyah observatory in Baghdad between 825 and 835. Using these observations, he estimated the Moon's diameter as 3,037 km (equivalent to 1,519 km radius) and its distance from the Earth as . In the 11th century, the Iraqi physicist Alhazen investigated moonlight through a number of experiments and observations, concluding it was a combination of the Moon's own light and the Moon's ability to absorb and emit sunlight.
By the Middle Ages, before the invention of the telescope, an increasing number of people began to recognize the Moon as a sphere, though many believed that it was "perfectly smooth".
Telescopic exploration before spaceflight
In 1609, Galileo Galilei drew one of the first telescopic drawings of the Moon in his book and noted 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. On maps, the dark parts of the Moon's surface were called maria (singular mare) or seas, and the light parts were called terrae or continents.
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. The first map of the Moon was made by the Belgian cosmographer and astronomer Michael van Langren in 1645. 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 (since called craters) the names of philosophers and astronomers.
In 1753, the Croatian Jesuit and astronomer Roger Joseph Boscovich discovered the absence of an atmosphere on the Moon. In 1824, Franz von Paula Gruithuisen explained the formation of craters as a result of meteorite strikes.
The since-disproven possibility that the Moon contains vegetation and is inhabited by selenites was seriously considered by major astronomers of the early modern period even into the first decades of the 19th century. In 1834–1836, Wilhelm Beer and Johann Heinrich Mädler published their four-volume Mappa Selenographica and the book in 1837, which firmly established the conclusion that the Moon has no bodies of water nor any appreciable atmosphere.
Space Race
The Cold War-inspired "space race" and "Moon 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 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, seen around the world as one of the pivotal events of the 20th century and human history.
The first artificial object to fly by the Moon was uncrewed Soviet probe Luna 1 on 4 January 1959, which went on to be the first probe to achieve a heliocentric orbit around the Sun. Luna 1 was designed to impact the surface of the Moon.
The first probe to impact the surface of the Moon was the Soviet probe Luna 2, which made a hard landing on September 14, 1959, at 21:02:24 UTC. The far side of the Moon was first photographed on 7 October 1959, by the Soviet probe Luna 3. Though vague by modern standards, the photos showed that the far side of the Moon almost completely lacked maria.
The first American probe to fly by the Moon was Pioneer 4 on 4 March 1959, which occurred shortly after Luna 1. It was the only success of eight early American probes that attempted to launch to the Moon.NASA.gov.
In an effort to compete with the Soviet successes, U.S. President John F. Kennedy proposed the Moon landing in a Special Message to the Congress on Urgent National Needs: Now it is time to take longer strides – time for a great new American enterprise – time for this nation to take a clearly leading role in space achievement, which in many ways may hold the key to our future on Earth....For while we cannot guarantee that we shall one day be first, we can guarantee that any failure to make this effort will make us last. ...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 in the long-range exploration of space; and none will be so difficult or expensive to accomplish. ...let it be clear that I am asking the Congress and the country to accept a firm commitment to a new course of action—a course which will last for many years and carry very heavy costs...
Ranger 1 launched in August of 1961, just three months after President Kennedy's speech. It would be three more years and six failed Ranger missions until Ranger 7 returned close-up photos of the lunar surface before impacting it in July 1964. A number of problems with launch vehicles, ground equipment, and spacecraft electronics plagued the Ranger program and early probe missions. These lessons helped in Mariner 2, the only successful U.S. space probe after Kennedy's famous speech to Congress and before his death in November 1963.NASA.gov. U.S. success rates improved greatly from Ranger 7 onward.
In 1966, the USSR accomplished the first soft landings and took the first pictures from the lunar surface during the Luna 9 and Luna 13 missions.
The U.S. followed Ranger with the Surveyor programNASA.gov – 24 January 2020, sending seven robotic spacecraft to the surface of the Moon. Five of the seven spacecraft soft-landed, investigating whether the regolith (dust) was shallow enough for astronauts to stand on the Moon.
In September 1968 the Soviet Union's Zond 5 sent tortoises on a circumlunar mission, followed by turtles aboard Zond 6 in November. On December 24, 1968, the crew of Apollo 8—Frank Borman, James Lovell and William Anders—became the first human beings 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 humans to walk on the lunar surface were Neil Armstrong, commander of the U.S. mission Apollo 11 and his fellow astronaut Buzz Aldrin.
The first robot lunar rover to land on the Moon was the Soviet vessel Lunokhod 1 on 17 November 1970, as part of the Lunokhod programme. Since then, the last human to stand 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 back to Earth by three Luna missions (Luna 16, 20, and 24) and the Apollo missions 11 through 17 (except Apollo 13, which aborted its planned lunar landing). Luna 24 in 1976 was the last Lunar mission by either the Soviet Union or the U.S. until Clementine in 1994. Focus shifted to probes to other planets, space stations, and the Shuttle program.
Before the "Moon race" the U.S. had preliminary projects for scientific and military Moon-bases: the Lunex Project and Project Horizon. Besides crewed landings, the abandoned Soviet crewed lunar programs included the building of a multipurpose Moon base "Zvezda", the first detailed project, complete with mockups of expedition vehicles and surface modules.
After 1990 Japan