Moon rockMoon rock or lunar rock is rock originating from Earth's Moon. This includes lunar material collected during the course of human exploration of the Moon, and rock that has been ejected naturally from the Moon's surface and landed on Earth as meteorites. Moon rocks on Earth come from four sources: those collected by six United States Apollo program crewed lunar landings from 1969 to 1972; those collected by three Soviet uncrewed Luna probes in the 1970s; those collected by the Chinese Lunar Exploration Program's uncrewed probes; and rocks that were ejected naturally from the lunar surface before falling to Earth as lunar meteorites.
Luna 20Luna 20 was the second of three successful Soviet lunar sample return missions. It was flown as part of the Luna program as a robotic competitor to the six successful Apollo lunar sample return missions. Luna 20 was placed in an intermediate Earth parking orbit and from this orbit was sent towards the Moon. It entered lunar orbit on 18 February 1972. On 21 February 1972, Luna 20 soft landed on the Moon in a mountainous area known as the Terra Apollonius (or Apollonius highlands) near Mare Fecunditatis (Sea of Fertility), 120 km from where Luna 16 had landed.
Luna programmeThe Luna programme (from the Russian word Луна "Luna" meaning "Moon"), occasionally called Lunik by western media, is a series of robotic spacecraft missions sent to the Moon by the Soviet Union and later Russia between 1959 and 2023. Fifteen were successful, each designed as either an orbiter or lander, and accomplished many firsts in space exploration. They also performed many experiments, studying the Moon's chemical composition, gravity, temperature, and radiation.
Sample-return missionA sample-return mission is a spacecraft mission to collect and return samples from an extraterrestrial location to Earth for analysis. Sample-return missions may bring back merely atoms and molecules or a deposit of complex compounds such as loose material and rocks. These samples may be obtained in a number of ways, such as soil and rock excavation or a collector array used for capturing particles of solar wind or cometary debris. Nonetheless, concerns have been raised that the return of such samples to planet Earth may endanger Earth itself.
Soviet space programThe Soviet space program (Kosmicheskaya programma SSSR) was the national space program of the former Union of Soviet Socialist Republics (USSR), active from 1955 until the dissolution of the Soviet Union in 1991. Soviet investigations in rocketry began with the formation of a research laboratory in 1921, but these efforts were hampered by the devastating war with Germany.
Luna 23Luna 23 was an uncrewed space mission of the Luna program developed by the Soviet Union. Luna 23 was a Soviet Moon lander mission which was intended to return a lunar sample to Earth. Launched to the Moon by a Proton-K/D, the spacecraft tipped over on its side and was damaged upon landing in Mare Crisium. The sample collecting apparatus could not operate and no samples were returned. The lander continued transmissions for three days after landing. In 1976, Luna 24 landed several hundred meters away and successfully returned samples.
Moon landingA Moon landing or lunar landing is the arrival of a spacecraft on the surface of the Moon. This includes both crewed and robotic missions. The first human-made object to touch the Moon was the Soviet Union's Luna 2, on 13 September 1959. The United States' Apollo 11 was the first crewed mission to land on the Moon, on 20 July 1969. There were six crewed U.S. landings between 1969 and 1972, and numerous uncrewed landings, with no soft landings happening between 22 August 1976 and 14 December 2013.
