Is our Earth actually two planets that fused together 4.5 billion years ago?
According to the report; “Oxygen isotopic evidence for vigorous mixing during the Moon-forming giant impact,” published on January 29th issue of Science…a mysterious proto-planet called Theia may have collided with the Earth…smashing off a piece to create our moon, and then fusing with this planet.
Science Alert writes; “If Theia simply side-swiped Earth and produced the Moon, as previously predicted, the Moon would be made up mainly of Theia, and Earth and Moon rocks would have different oxygen isotope ratios. But this wasn’t the case.”
The Daily Mail breaks down the giant impact theory of the Moon’s creation.
HOW THE MOON FORMED: THE GIANT IMPACT HYPOTHESIS
This is called the giant impact hypothesis.
The hypothesis claims the moon is debris left over following an indirect collision between our planet and an astronomical body approximately 4.5 billion years ago.
The colliding body is sometimes called Theia, after the mythical Greek Titan who was the mother of Selene, the goddess of the Moon.
But one mystery has persisted, revealed by rocks the Apollo astronauts brought back from the moon – why are the moon and Earth so similar in their composition?
Several different theories have emerged over the years to explain the similar fingerprints of Earth and the moon.
Perhaps the impact created a huge cloud of debris that mixed thoroughly with the Earth and then later condensed to form the moon.
Or Theia could have, coincidentally, been isotopically similar to young Earth.
A third possibility is that the moon formed from Earthen materials, rather than from Theia, although this would have been a very unusual type of impact.
Here’s an older video showing what a collision with Theia might have looked like.
And here’s an unrelated video of a giant asteroid colliding with the Earth.