The standard giant-impact hypothesis suggests that a Mars-sized body, called Theia, impacted the proto-Earth, creating a large debris ring around Earth, which then accreted to form the Moon. This collision also resulted in the 23.5° tilted axis of the Earth, thus causing the seasons.

How was the Moon born?

The Moon has been circling the Earth for more than four billion years. ... Today, most scientists believe it is the 'Earth's child'. It was born when a wandering planet crashed into the young Earth. Huge amounts of material were thrown into space, eventually coming together to form the Moon.

How was the Moon first formed?

The giant impact theory – which states that the Moon formed from the a collision between the early Earth and a rocky body called Theia – has become the front runner among the explanations. ... It smashed into the developing Earth 4.5 billion years ago.