The Frost Line
Like many space-related misconceptions that refuse to go away, there is still a widely held belief that our planet is the only place in our Solar System where water exists. This couldn’t be further from the truth. Water is abundant in space. We find it everywhere. Break H2O down into its two main constituents, and you immediately realize that hydrogen and oxygen are respectively the first and third most common elements in space. That’s a lot of matter capable of forming water.