A detailed simulation of Theia crashing into Earth. While the collision was violent, it was not energetic enough to melt the Earth's lower mantle -- meaning that remnants of Theia could be preserved, ...

Computer simulations suggest that a collision with another planetary object early in Earth’s history may have provided the heat to set off plate tectonics. By Lucas Joel Some 4.5 billion years ago, ...

Earth didn't exactly start out ready to support life, but scientists now have a better idea of how the essential elements for life ended up on our planet, according to a study published Wednesday in ...

A Mars-size object called Theia smashed into Earth, and the debris coalesced into the moon. Now scientists believe they may have identified pieces of Theia at the bottom of Earth’s mantle. A new study ...

Most scientists agree that a major collision 4.5 billion years ago with a protoplanet named Theia formed the Earth-Moon system. Now, a new study from the University of Nevada argues that, out of the ...

The Moon formed in a catastrophic impact between the proto-Earth (Gaia) and a Mars-sized object we call Theia. The collision happened around 4.5 billion years ago but its effects are still with us.