Origin of the Moon

In the history of astronomy, numerous hypotheses have been proposed to explain the formation of the Moon. Some suggest that the Moon formed from a impact event, while others suggest it may have been captured or formed alongside Earth.

Name of hypothesis	Proposed by	The hypothesis	Disproven?
Giant-impact hypothesis	Reginald Daly	Suggests that the Moon formed from the debris of a collision between the early Earth and a Mars-sized protoplanet named Theia, approximately 4.5 billion years ago.	No
Fission theory	George Darwin	Suggests that the Moon originated from material ejected due to Earth's rapid rotation during its early molten state.	Yes
Capture theory	Thomas Jefferson Jackson See	Suggests that the Moon formed elsewhere in the solar system and was later captured by Earth's gravitational field.	Yes
Co-formation theory	Édouard Roche	Suggests that Earth and the Moon formed simultaneously from the same protoplanetary disk of gas and dust in the early solar system.	Yes
Synestia hypothesis	Sarah T. Stewart and Simon Lock	Suggests that the Moon formed within a synestia—a rapidly spinning, doughnut-shaped mass of vaporized rock resulting from a high-energy, high-angular momentum collision between planetary bodies.	Not entirely
Multiple-impact hypothesis	Nikolai Gorkavyi	Suggests that the Moon formed through a series of smaller impacts.	Not entirely