High Quality Content by WIKIPEDIA articles! The question of the origin of water on Earth, or more accurately put, the question of why there is clearly more water on the Earth than on the other planets of the Solar System, has not been clarified. There are various popular theories as to how the world's oceans were formed over the past 4.6 billion years. Some of the most likely contributing factors to the origin of the Earth's oceans are as follows: The cooling of the primordial Earth to the point where the outgassed volatile components were held in an atmosphere of sufficient pressure for the stabilization and retention of liquid water.