The collision between Earth and Speedy Theia, resulting in the formation of the moon
Every day new things are discovered about the world around us. But that’s not it. Every day, scientists find out that previously confirmed theories were wrong, and that something else actually happened. Well, probably not every day, but statistics say that it happens at least every week. One of the most recent cases of such previously misguided intel is in regards to our natural satellite, as researchers found out that the moon resulted from Earth’s head-on collision with Theia.
Of course, scientists have been speculating for a while regarding the formation of the moon, and the majority of the astrophysics world agreed that a collision between the newly forming planet Theia and the still young Earth is what resulted in the moon in the first place.
However, it was believed that collision was at a 45 degree angle, more like a passing side-swipe hit than a full, head-on collision.
As the Earth was still young and probably still in its molten rock phase, the newly formed planet embryo or just the very young planet which is referred to now as Theia happened to head towards it and hit our home planet head-on.
This resulted in the violent, deconstructive death of Theia, but also in a large chunk of Earth being destroyed.
Still in a stage in its life where reconstruction was possible because of its molten rock surface, Earth used its gravity to divide the remnants of Theia between itself and the chunk of it which flew off and started orbiting around it.
This is how the young Theia died after the collision, pieces of it being incorporated into the Earth, and other pieces joining the chunk of Earth that flew off and forming the moon.
With this happening billions of years ago, the two had time to adjust and settle into their new shapes and orbits.
This discovery was made after a team of researchers led by an UCLA professor of cosmochemistry and geochemistry compared several moon rocks to several pieces of rock from the Earth’s mantle, Arizona, and Hawaii.
Pretty much all the other planets have their own different “fingerprint” based on the type of oxygen atoms present in their composition; and since the moon and the Earth have virtually identical fingerprints, it means that they are formed from exactly the same rocks.
This is how the team was able to determine that the previous assumption of a 45 degree angle was mistake, and that the moon resulted from Earth’s head-on collision with Theia.
Image source: Wikimedia
