Scientists discover new things about our planet every day. Some are small, some are huge, and others are just mind blowing. It is even better for the discoverer when a previously theorized event is finally confirmed after a long while of being just a theory. One such case involved our natural satellite until recently, when a team of researchers discovered the Earth and moon formed after head-on collision with Theia.
Theia vs. Earth
Don’t worry, scientists have been relatively sure about the moon’s origin for quite a while, and most of the scientific world agreed with the theory. Indeed, the fact that a young planet now named Theia collided with the blue planet resulting in the moon has been known for a while.
The debate was regarding the way the Earth was hit. The main theory, up until very recently, was that the collusion took place at a 45 degree angle, with Theia just scraping our ball of rock. But a few days ago, this theory was utterly shattered, much like Theia was.
As it turns out, while Earth was still in its molten rock phase, able to take a hit without too many issues, Theia, then a planet embryo, collided due the forces of gravity with our planet in a violent, head-on fashion. This resulted in Theia being completely shattered, but also in a huge chunk of Earth flying off.
With Earth basically being a ball of lava and rock with a pretty strong gravity, it just used parts of the now shattered Theia to form itself back together. Due to the planet’s gravity, the chunks of rock that flew off the planet merged with the remaining chunks of Theia and started orbiting the Earth.
This is how the Earth and moon as we know them came to be – with the blue planet integrating part of a destroyed planet and making it its own. And while it was at it, and there was still extra material, why not accessorize?
Determining the facts
The process of the discovery was also quite interesting although not nearly as interesting as how our planet and its natural satellite came to be – a team of researchers examined the geological compositions of rocks from Arizona, Hawaii, and the Earth’s mantle and compared them against moon rocks.
Since all the planets have their own different geological fingerprint based on the types of atoms – particularly oxygen atoms – present in their composition, and since the Earth’s and the moon’s were virtually identical, it means that both interstellar bodies are made of the exact same materials.
Image source: Wikimedia