The Moon is Earth's natural satellite, studied for its geological and gravitational interactions.The Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. It formed about 4.5 billion years ago, likely from debris ejected into orbit after a collision between Earth and a Mars-sized body. Its surface is covered with impact craters, and the dark areas — the lunar maria — are solidified basaltic lava plains. The lack of atmosphere leads to extreme temperature variations: from +127°C during the day to -173°C at night.
Ancient civilizations worshipped the Moon and used its phases for calendars. In 1609, Galileo Galilei used a telescope to sketch lunar mountains and craters, disproving the idea of perfect celestial spheres. In 1665, Robert Hooke in 'Micrographia' described lunar craters in detail and suggested their impact origin. The space race began in the 20th century: in 1959, Luna 2 reached the surface, and in 1969, Apollo 11 made the first manned landing. Analysis of returned samples revealed a striking similarity to Earth rocks, strengthening the impact hypothesis. Modern missions like LRO and Chang'e continue to map the Moon and search for water ice in polar craters.
The motion of the Moon is described by Kepler's laws and the law of universal gravitation. The orbit is perturbed by the Sun and planets, leading to librations that allow us to see slightly more than half the surface. The main feature is tidal locking: due to tidal forces, the Moon always faces Earth with the same side, as its rotation period around its axis equals its orbital period. This results from the dissipation of tidal friction energy. The Moon's gravitational influence on Earth causes tides, which slow Earth's rotation and transfer orbital momentum to the Moon, increasing its distance.
Stabilizes Earth's rotation axis, causing tides that affect navigation, coastal ecosystems and potentially used for tidal energy.
From Earth, only one side of the Moon is visible due to tidal locking (gravitational synchronization of rotation), but that doesn't mean the far side is always dark — day and night alternate there just like on the visible side. The first images of the far side were taken by the Soviet probe Luna 3 in 1959.
























