The prevailing hypothesis today is that the Earth–Moon system formed as a result of a giant impact: a Mars-sized body hitting the newly formed proto-Earth, blasting material into orbit around it, which accreted to form the Moon. Giant impacts are thought to have been common in the early Solar System. Computer simulations modelling a giant impact are consistent with measurements of the angular momentum of the Earth–Moon system and the small size of the lunar core. These simulations also show that most of the Moon came from the impactor, not from the proto-Earth. However more recent tests suggest more of the Moon coalesced from the Earth and not the impactor. Meteorites show that other inner Solar System bodies such as Mars and Vesta have very different oxygen and tungsten isotopic compositions to the Earth, while the Earth and Moon have near-identical isotopic compositions. Post-impact mixing of the vaporized material between the forming Earth and Moon could have equalized their isotopic compositions, although this is debated.
Most likely a huge asteroid collided with the earth when it was forming. A piece of earth got ripped away. The forming earth had a greater gravity and pulled the broken off chunk into orbit around itself. Then the debris surrounding each object got pulled into them.
Wow it makes me wonder what the heck they teach in science classes any more!! Ok when Earth was forming an asteroid collided with it & a piece of earth was ripped away & was mixed with that & other debris in space to form the moon.
During the creation of the Earth, a Mars-sized object crashed into it, sending debris into space. With gravity, the moon then formed and the Earth kept forming. And now, in the present, we have a big blue rock with water on it with a smaller white rock circling it, and apparently science teachers who aren't teaching this stuff on the big blue rock.