How did the Moon form?

Before the Apollo mission research, there were three theories about how the Moon formed.

1. Capture theory suggests that the Moon was a wandering body that was captured by Earth's gravity as it passed nearby.
2. Accretion theory suggests that the Moon was created along with Earth at its formation.
3. The fission scenario proposes that the Earth spun so fast that some material broke away and began to orbit the planet.

Today, the giant-impact theory is widely accepted. It proposes that Earth and a small planet collided. The debris from this impact collected in orbit around Earth to form the Moon.

The Apollo mission brought back rock and soil from the Moon. It showed that the Earth and Moon share chemical and isotopic similarities, suggesting a linked history.

The minerals on the Moon contain less water than similar terrestrial rocks. The Moon has material that forms quickly at a high temperature.