How would have the moon originated?

The moon was formed due to the collision of a celestial body with the earth, which was similar to the planet Mars in size.

Additional information:

There are three theories that answer the creation of the moon: the giant impact hypothesis, the fission theory, and the capture theory.

1) Giant impact hypothesis

According to this theory the Mars-sized body collided with Earth as a result large scattered pieces thrown into space eventually collected into a single natural satellite.

2) The Fission Theory

This theory proposes that the Moon spun off from Earth early in the history of the solar system. The Pacific basin was the scar left by the tearing away of the Moon.

3) Capture theory

This theory proposes that the Moon was created somewhere else in the solar system and captured by Earth's gravitational field as it wandered too close to the planet.