If you asked someone who was reasonably scientifically literate how Earth got its water, they’d likely tell you it came from asteroids—or maybe comets and planetesimals, too—that crashed into our planet in its early days. There’s detail, nuance, and uncertainty around that idea, but it’s widely believed to be the most likely reason that Earth has so much water.
But a new explanation for Earth’s water is emerging. It says that the water comes along for the ride when Earth formed out of the solar nebula.
If that’s correct, it means that most rocky planets might have water for at least a portion of their lives.Continue reading “There Might Be Water On All Rocky Planets”