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  4. Moons

Moons of Earth

Earth has 1 known natural satellite.

About Earth's Moon System

Earth has a single natural satellite: the Moon, also known as Luna. It is the fifth-largest moon in the solar system and the largest relative to its host planet, with a diameter of 3,474 km -- about one-quarter the size of Earth. The Moon is believed to have formed roughly 4.5 billion years ago when a Mars-sized body called Theia collided with the early Earth, ejecting debris that coalesced into our natural satellite. The Moon's gravitational pull drives Earth's ocean tides and helps stabilize the planet's axial tilt, which is essential for maintaining relatively stable seasonal cycles. Its surface is marked by impact craters, dark volcanic plains called maria, and a fine layer of regolith dust.

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Explore Other Moon Systems

Mars (2)Jupiter (95)Saturn (146)Uranus (28)Neptune (16)Pluto (5)
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