How Did Earths First Oceans Form?
Current theory is that as the Earth cooled and coalesced, the various elements within it seperated. Denser iron went towards the middle of the planet, and less dense material such as water came towards the surface. Thus, early volcanism created the first oceans. The asteroid theory is a bit similar, except that early in our planet’s history everything was an asteroid. Think of giant gobs of stuff including iron-rich asteroids and water-rich asteroids floating around, eventually collapsing into a massive ball of stuff. As it coalesces, the denser stuff moves towards the middle and the lighter stuff moves towards the outside. That is kind of what happened 5 billion years ago. That was a long time ago, however, and nobody was around back then. Our best guesses are inferred from other objects in the solar system. Saturn’s moon Europa is rather interesting, because the entire surface is water (ice), and it is not known how deep that water goes, exactly where it came from, and why there is s
