the collision with a comet created the Moon

...this planet, it transpired, had 'burst' and two fragments broken off from it had flown into space.

...the planet Earth and the comet Kondoor collided, and collided so violently that from the shock, as I have already told you, two large fragments broke off from the planet Earth and flew into space.

Beelzebub Chapter 9 "The cause of the genesis of the Moon"