Formation of the Moon

Today in class I learnt about some theories on how the moon was formed, one of them being the Giant Impact Theory.

What is the Giant Impact Theory?

The Giant Impact Theory is the most supported theory by the scientific community to date. This theory suggests that the moon formed when an object collided with earth during the days of our early solar system.

Where did this object come from? What was it?

Believe it or not, the early solar system was a terribly violent place. Because of this, a vast number of bodies were created and never reached full planetary status. One of these bodies very well could have collided with earth, close to the period of time when the planet was created.

This event threw vaporized chunks of earth into space, which gravity bound the ejected particles together and created a moon. This body that collided with earth is known as "Theia".

Is there evidence that can support this event?

• The earth-moon system contains a high angular momentum... which is SIGNIFICANTLY higher than other terrestrial planets. It's theorized that a giant impact may have supplied this excess momentum.

• The compositions of the earth and the moon are practically identical with the only difference being that the moon lacks an iron core... This supports the theory greatly because the moon would've formed from the less dense materials of the earth's crust.

• The spin of earth and the moon's orbit have similar orientations.

I hope you enjoyed reading this!