How many moons does Earth have?
Earth has one natural moon, simply called the Moon. However, small asteroids called quasi-moons and mini-moons sometimes travel near Earth for a time.
The Moon is about 3,474 kilometers across, roughly a quarter of Earth's diameter, making it unusually large compared to its planet. Scientists think it formed about 4.5 billion years ago when a Mars-sized object crashed into the young Earth, throwing debris into orbit that came together.
Quasi-moons are asteroids that orbit the Sun in a path similar to Earth's, so they seem to circle our planet from our point of view. One example is Kamo'oalewa, which may be a fragment of the Moon. Mini-moons are small asteroids temporarily captured by Earth's gravity. In late 2024, an asteroid called 2024 PT5 became a mini-moon for about two months.
Human-made moons
Earth also has thousands of artificial satellites, but these are not counted as moons. Only natural bodies that orbit a planet are considered moons.
Did You Know?
The Moon is slowly moving away from Earth, by about 3.8 centimeters per year, about as fast as fingernails grow.