Moon Derives From Earth, Space Object, Study Says

Science has a better understanding of how and when the moon came to be thanks to a team of German geochemists who compared ratios of trace elements in rocks from the Earth, the moon, Mars, and meteorites.

Most astronomers subscribe to the so-called “cratering” theory to explain the moon’s creation: Billions of years ago, a Mars-sized body slammed into Earth, projecting a mixture of rocky debris into space, some of which lumped together to form the moon. The remaining debris rained back down on Earth.