Answer:
Giant-Impact Theory
Step-by-step explanation:
To describe the origin of moon, there are various theories. One of the theories and the most accepted one is the Giant-impact theory. According to this theory, a Mars-sized object known as Theia collided with the Earth. The debris from the collision combined together to form a body which started orbiting the Earth. This object is now known as the Moon. The evidence supporting this theory is the similar composition of moon and the outer portion of the Earth. This was determined by comparing the Lunar rocks composition and the rocks on Earth.