Impact Theory

Asteroid Impact Theory of The Moon

 * The Impact Theory(also called the Giant-Impact Theory) suggests that Earth's moon was created via a roughly Mars-sized asteroid indirectly(i.e. not head-on) colliding with the Earth approximately 4.5 billion years ago. According to the theory, the debris in which was sheared off of the early Earth collected in a sort of rapidly rotating disk about the largest chunk of the left-over asteroid, eventually slowing and cooling in relation to the Earth.

Supporting Evidence

 * The strongest units of supporting evidence to the Impact Theory is the moon's surface composition being almost identical to that of the composition of the Earth's mantle, evidence that the moon was at one time molten, the fact that the Moon and Earth have identical rotational periods.

Opposing Evidence
