Answer:
In previous models, the moon either formed concurrently with Earth in its accretion disk, or was captured when its orbit crossed that of Earth's, and was captured in Earth's gravitational field.
Step-by-step explanation:
Nowadays, scientists have not yet managed to discover how the moon originated, but many theories and models have been created to explain in a speculative way how the formation of this satellite occurred.
The model that was most accepted earlier was called the nebular model. This model claimed that the moon was formed simultaneously with the earth, or was a star that was captured when its orbit crossed the earth's orbit, allowing the earth's gravitational field to prevent it from leaving.
However, the currently accepted model states that the moon was formed through a collision between the earth and a celestial body the size of Mars.