How many moons does Earth have?

Earth has one natural moon. It is usually called the Moon with a capital letter because it is Earth’s unique, well-known natural satellite, although “moon” is also a general term for satellites orbiting other planets and small bodies.

The Moon travels around Earth at an average distance of about 384,400 kilometers and is tidally locked, meaning its rotation period matches its orbital period. That is why observers on Earth see nearly the same lunar hemisphere over and over. Its gravity also helps produce ocean tides and contributes to the long-term stability of Earth’s axial tilt.

People sometimes hear about “second moons” or “minimoons.” These are usually near-Earth asteroids temporarily captured by Earth’s gravitational influence, or quasi-satellites that orbit the Sun in a way that makes them appear to accompany Earth. They are not permanent natural satellites like the Moon. The Moon formed roughly 4.5 billion years ago and was first visited by humans during Apollo 11 in 1969.