This is a theory of planet Tiamat and the origins of Earth. This theory was derived by Zecharia Sitchin, author of the 12th planet in which he would explain.
Based on his studies, he believed there was another planet in our solar system, Tiamat.
Planet Tiamat existed billions of years ago before Earth was even a thought.
It was located between Mars and Jupiter. He theorized based on ancient Sumerian tablets, that planet Nibiru and its orbit collided with his planet.
Nibiru was the home of the ancient Daconan race known as the Anunnaki.
At the time of this collision, an ancient alien race, far more advanced than we ever dreamed was living on planet Tiamat.
The result would be total loss of life. But complete annihilation would only occur to half a planet. The other half would end up in orbit what we call Earth.
The half that got destroyed would end up being the asteroid belt. Nibiru would sustain damage but continue on its path until millions of years later when the Earth was finally habitable. That’s when they show up and use us to mine gold.