Where did all the water come from?

Hipster_Nebula wrote:Jupiter's gravity would have pulled icy objects now in the Kuiper belt towards earth, in the early formation of the solar system, nothing to do with Jupiter itself.

Hipster_Nebula wrote:

Recent measurements of the chemical composition of Moon rocks suggest that Earth was born with its water already present. Investigating lunar samples carried to Earth by the Apollo 15 and 17 missions found a deuterium-to-hydrogen ratio that matched the isotopic ratio in carbonaceous chondrites. The ratio is also similar to that found in water on Earth. The findings suggest a common source of water for both objects. This supports a theory that Jupiter temporarily migrated into the inner Solar System, destabilizing the orbits of water-rich carbonaceous chondrites. As a result, some of the bodies could have fallen inwards and become part of the raw material for making Earth and its neighbors.^[4] The discovery of water vapor out-gassing from Ceres provides related information on water-ice content of the asteroid belt.^[5]

Hipster_Nebula wrote:Obviously I'm not a scientist but all this would have been happening in the turbulent formation of the solar system before the earth was formed, so things as we know it wouldn't have been established at that point, such as Jupiters current orbit.