According to researchers at NASA, the moon— and Earth— was part of a massive planetary collision with masses that were five-times the size of Mars. During this collision, the outer layers of the Earth were vaporized to form a synestia, or a continuous body of material.
With synestias, it is possible that the Earth could have been transformed into an “extended, substantially vaporized body.” This dictated how the Earth’s core was formed, as well as potentially making way for our oceans and atmospheres to develop—and, possibly, how the moon then came to be.
The most widely-accepted theory until this point—dubbed the “giant impact hypothesis”—suggested that the moon formed upon a gargantuan impact with a mass called Theia, which supposedly collided with Earth in the early years of our Solar System’s existence.
In this scenario, the moon formed from debris pushed into Earth’s orbit by a collision with a smaller proto-planet. However, an impact with a planet roughly the size of Mars, alone, would most likely have left the Earth and moon with different chemical composition, which is not the case. It could have also increased the rotational speeds of both planets.
Though the new models are not definitive, scientists can ascertain that planetary impacts like the one now believed to have created the moon could have taken place a number of times in our planet’s history.
Top photo by Per / Flickr, CC BY-SA 2.0
Natalie Wickstrom is a freelance writer based in Athens, Georgia. She probably wrote this piece to the tune of a movie score whilst chewing gum.