In geophysical terms, the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is 3,474 km (2,159 mi), roughly one-quarter of Earth's (about as wide as the contiguous United States).
Moon, Earth’s sole natural satellite and nearest celestial body. Known since prehistoric times, it is the brightest object in the sky after the Sun. Its name in English, like that of Earth, is of Germanic and Old English derivation.Moon - Craters, Highlands, Maria: The Moon is a spherical rocky body, probably with a small metallic core, revolving around Earth in a slightly eccentric orbit at a mean distance of about 384,000 km (238,600 miles).
The Moon is one of the most recognisable objects in the solar system. This proximity to Earth has given it immeasurable cultural significance and means it plays a key role in Earth's tides. Explore facts about this small but mighty celestial body.