The Moon probably formed:
A) out of a collision between Earth and a Mars-sized object.
B) when the Earth's gravity captured a planetesimal.
C) when the accretion disk around Earth fragmented.
D) when planetesimals collided to form a more massive object.

Question

Quizplus · Accepted Answer

The leading theory for the formation of the Moon is the giant impact hypothesis, which states that a Mars-sized object collided with Earth early in its history, ejecting debris into space that eventually coalesced to form the Moon.

The Moon Probably Formed