NASAThe National Aeronautics and Space Administration (NASA ˈnæsə) is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research, and space research. Established in 1958, NASA succeeded the National Advisory Committee for Aeronautics (NACA) to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science.
Lunar mareThe lunar maria (ˈmɑːri.ə ; mare ˈmɑːreɪ ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed maria, by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to the naked eye. The maria cover about 16% of the lunar surface, mostly on the side visible from Earth.
Geology of the MoonThe geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar science") is quite different from that of Earth. The Moon lacks a true atmosphere, and the absence of free oxygen and water eliminates erosion due to weather. Instead, the surface is eroded much more slowly through the bombardment of the lunar surface by micrometeorites. It does not have any known form of plate tectonics, it has a lower gravity, and because of its small size, it cooled faster.
Chang'e 4Chang'e 4 (tʃa:ŋˈə; ) is a robotic spacecraft mission in the Chinese Lunar Exploration Program of the CNSA. China achieved humanity's first soft landing on the far side of the Moon with its touchdown on 3 January 2019. A communication relay satellite, Queqiao, was first launched to a halo orbit near the Earth–Moon L2 point in May 2018. The robotic lander and Yutu-2 () rover were launched on 7 December 2018 and entered lunar orbit on 12 December 2018, before landing on the Moon's far side.
Lunar orbitIn astronomy, lunar orbit (also known as a selenocentric orbit) is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by spacecraft around the Moon. The altitude at apoapsis (point farthest from the center of attraction) for a lunar orbit is known as apolune, apocynthion, or aposelene, while the periapsis (point closest to the center of attraction) is known as perilune, pericynthion, or periselene, from names or epithets of the moon goddess.
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.
SelenographySelenography is the study of the surface and physical features of the Moon (also known as geography of the Moon, or selenodesy). Like geography and areography, selenography is a subdiscipline within the field of planetary science. Historically, the principal concern of selenographists was the mapping and naming of the lunar terrane identifying maria, craters, mountain ranges, and other various features. This task was largely finished when high resolution images of the near and far sides of the Moon were obtained by orbiting spacecraft during the early space era.
Apollo 15Apollo 15 (July 26 - August 7, 1971) was the ninth crewed mission in the United States' Apollo program and the fourth to land on the Moon. It was the first J mission, with a longer stay on the Moon and a greater focus on science than earlier landings. Apollo 15 saw the first use of the Lunar Roving Vehicle. The mission began on July 26 and ended on August 7, with the lunar surface exploration taking place between July 30 and August 2.
Orion (spacecraft)Orion (officially Orion Multi-Purpose Crew Vehicle or Orion MPCV) is a partially reusable crewed spacecraft used in NASA's Artemis program. The spacecraft consists of a Crew Module (CM) space capsule designed by Lockheed Martin and the European Service Module (ESM) manufactured by Airbus Defence and Space. Capable of supporting a crew of six beyond low Earth orbit, Orion can last up to 21 days undocked and up to six months docked. It is equipped with solar panels, an automated docking system, and glass cockpit interfaces modeled after those used in the Boeing 787 Dreamliner.
Artemis 1Artemis 1, officially Artemis I and formerly Exploration Mission-1 (EM-1), was an uncrewed Moon-orbiting mission. As the first major spaceflight of NASA's Artemis program, Artemis 1 marked the agency's return to lunar exploration after the conclusion of the Apollo program five decades earlier. It was the first integrated flight test of the Orion spacecraft and Space Launch System (SLS) rocket, and its main objective was to test the Orion spacecraft, especially its heat shield, in preparation for subsequent Artemis missions.
Near side of the MoonThe near side of the Moon is the lunar hemisphere that always faces towards Earth, opposite to the far side. Only one side of the Moon is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth—a situation known as tidal locking. The Moon is directly illuminated by the Sun, and the cyclically varying viewing conditions cause the lunar phases. Sometimes the dark portion of the Moon is faintly visible due to earthshine, which is indirect sunlight reflected from the surface of Earth and onto the Moon.
Apollo 10Apollo 10 (May 18–26, 1969) was the fourth human spaceflight in the United States' Apollo program and the second to orbit the Moon. NASA, the mission's operator, described it as a "dress rehearsal" for the first Moon landing (Apollo 11, two months later). It was designated an "F" mission, intended to test all spacecraft components and procedures short of actual descent and landing.
