News > Earth’s water: Where did it all come from?

Earth’s water: Where did it all come from?

There are two hypotheses on where Earth’s water came from. Some scientists think that most of Earth’s water came from meteoroids (asteroids become known as meteors when they collide with a planet) that struck the Earth. The other, more recent hypothesis, suggests that most of Earth’s water was already here inside the planet, and it came to the surface over time. The answer to our question is likely a combination of these two hypotheses.