Add Yahoo as a preferred source to see more of our stories on Google. Artist’s impression of the planet Theia colliding with ancient Earth to create the moon. (MPS/Mark A. Garlick) Roughly four and a ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon.

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying itself, melting large portions of our planet’s mantle and ejecting a huge debris disk that later pulled ...