The theory goes that 4.5 billion years ago, the protoplanet Theia collided with the precursor to our Earth. Researchers have now found amazing traces inside our planet.
This is how the moon could have formed: A Mars-sized protoplanet called Theia collided with Earth’s precursor 4.5 billion years ago. As a result of the collision, ejected material from both the Earth’s progenitor and the mantle of Theia was captured by the proto-Earth’s gravity field. In a disk of dust around Earth’s progenitor, it clumped together and eventually formed today’s moon. The earth absorbed the other part of the Theia fragments. There is nothing left of Theia itself, the celestial body was mixed into the proto-Earth and the proto-Moon – at least that is what the so-called collision theory says. But how can this be proven?