<P> The giant - impact hypothesis , sometimes called the Big Splash , or the Theia Impact suggests that the Moon formed out of the debris left over from a collision between Earth and an astronomical body the size of Mars , approximately 4.5 billion years ago , in the Hadean eon ; about 20 to 100 million years after the solar system coalesced . The colliding body is sometimes called Theia , from the name of the mythical Greek Titan who was the mother of Selene , the goddess of the Moon . Analysis of lunar rocks , published in a 2016 report , suggests that the impact may have been a direct hit , causing a thorough mixing of both parent bodies . </P>
<P> The giant - impact hypothesis , sometimes called the Big Splash , or the Theia Impact suggests that the Moon formed out of the debris left over from a collision between Earth and an astronomical body the size of Mars , approximately 4.5 billion years ago , in the Hadean eon ; about 20 to 100 million years after the solar system coalesced . The colliding body is sometimes called Theia , from the name of the mythical Greek Titan who was the mother of Selene , the goddess of the Moon . Analysis of lunar rocks , published in a 2016 report , suggests that the impact may have been a direct hit , causing a thorough mixing of both parent bodies . </P>
the idea that the moons development began when a large object collided with earth is called the
the idea that the moons development began when a large object collided with earth is called the
The giant - impact hypothesis , sometimes called the Big Splash , or the Theia Impact
The giant - impact hypothesis , sometimes called the Big Splash , or the Theia Impact