THE Earth is actually made up of two planets, scientists have claimed.

A smaller planet, Theia, slammed into an early Earth so hard that the planets effectively mixed together.

Moon was formed by debris from a violent head-on collision between Earth and Theia.

The traditional belief regarding the origins of Earth and the Moon — that a smaller planet, Theia, grazed the Earth and sent a portion into Earth’s orbit — is false, according to Professor Edward Young from the University of California, Los Angeles (UCLA).

After studying Moon rocks brought back by astronauts on the Apollo missions, the university made a groundbreaking new discover that the Moon did not have the chemical composition made up of Theia.

“We don’t see any difference between the Earth’s and the Moon’s oxygen isotopes; they’re indistinguishable,” he said.

“Theia was thoroughly mixed into both the Earth and the Moon, and evenly dispersed between them.

“This explains why we don’t see a different signature of Theia in the Moon versus the Earth.”

The collision between Theia and Earth would have taken place approximately 100 million years after the initial formation of Earth, which was over 4.5 billion years ago.

In 2014, a team of German scientists said that the Moon also has its own unique ratio of oxygen isotopes — different from Earth’s.

But the new research finds that is not the case.