Well, the reality is oddly close to the fantasy, actually. According to Wikipedia (Origin_of_water_on_Earth): > The region of the protoplanetary disk closest t

Well, the reality is oddly close to the fantasy, actually. According to Wikipedia (Origin_of_water_on_Earth): > The region of the protoplanetary disk closest to the Sun was very hot early in the history of the Solar System, and it is not feasible that oceans of water condensed with the Earth as it formed. Further from the young Sun where temperatures were cooler, water could condense and form icy planetesimals. The boundary of the region where ice could form in the early Solar System is known as the frost line (or snow line), and is located in the modern asteroid belt, between about 2.7 and 3.1 astronomical units (AU) from the Sun.[18][19] It is therefore necessary that objects forming beyond the frost line–such as comets, trans-Neptunian objects, and water-rich meteoroids (protoplanets)–delivered water to Earth.