The moon is on a synchronous rotation with the Earth, which always shows the same side of the Earth, with the near side marked by a dark volcanic mare found between the high plateau of the crust and the prominent collision crater. The moon is the brightest celestial body after the Sun. Although the Moon is very white and bright, the surface of the Moon is actually dark, with a slightly higher degree of molten asphalt. Since ancient times, its prominent position in the sky and its regular phases has influenced many cultures, including the language, dating, art, and mythology. The influence of Moon's gravity causes tides in the oceans and an extension of time on Earth's day. The Moon's orbital distance from Earth today is about thirty times the diameter of the Earth, causing the Moon's size to appear in the sky almost as large as the size of the Sun, thus allowing the Moon to cover the Sun and result in a total solar eclipse. The Moon's linear distance from Earth is currently increasing at a rate of 3.82 ± 0.07 cm per year, although this rate is not constant. [8]
The moon is estimated to form about 4.5 billion years ago, shortly after the formation of Earth. Although there are a number of hypotheses about the origin of the Moon, the most accepted hypothesis today explains that the Moon is formed from fragments released after a celestial body the size of Mars collided with Earth.
The Moon is the only celestial body other than Earth that has been landed by humans. The Soviet Union Luna program was the first vehicle to reach the Moon with a nirawak spacecraft in 1959; the US NASA Apollo program is the only manned space mission to have reached the Moon to date, beginning with the launch of the Apollo 8 manned mission orbiting the Moon in 1968, followed by six manned landing missions between 1969 and 1972, the first of which Apollo 11. This mission returns to Earth with 380 kg of Moon, which is used to develop a geological understanding of the origin, the formation of deep structures, and the geological history of the Moon.
After the Apollo 17 mission in 1972, the moon was only visited by the nirawak spacecraft. These missions are generally orbital missions; since 2004, Japan, China, India, the United States and the European Space Agency have launched the Moon orbiting spacecraft, which has contributed to the discovery of water ice in the Moon's polar crater. Post Apollo, two countries have also sent rover missions to the Moon, the last Soviet Lunokhod mission in 1973, and the continuing mission of Chang'e 3RRC, which launched the Yutu rover on December 14, 2013.
Future manned missions to the Moon have been planned by various countries, both government-funded or private. Under the Space Agreement, the Moon remains free to be explored by all countries for peaceful purposes.