The origin of water on the blue planet and remains an unsolved riddle for all mankind, as well as origin of the planet Earth. Still disputes among the scientists of the whole world working in this direction do not cease.
There are several assumptions which are essentially differing from each other which divided scientific minds into two camps, some are supporters of a meteoric or "cold" geogenesis, others opposite prove "hot" origin of the planet. The first believe that Earth originally was a big firm cold meteorite, the second claim that the planet was more hotly and extremely dry. Only that fact that such vital element as water, appeared on Earth at a stage of formation of the blue planet, that is long before appearance of the person is indisputable.
Hypothesis of "cold" origin of the planet
According to a hypothesis of "cold" origin the globe at the beginning of existence was cold. Further thanks to disintegration of radioactive elements the depths of the planet began to be warmed, as became the reason of volcanic activity. The thrown-up lava took out various gases and vapors of water on a surface. Further at gradual cooling of the atmosphere there was a condensation of a part of water vapor that resulted in a huge number of precipitation. Continuous rains throughout the millennia at the initial stage of formation of the planet became a source of the water which filled oceanic hollows and formed the World Ocean.
Hypothesis of "hot" origin of the planet
Most of the scientists making a hypothesis of a "hot" geogenesis do not connect emergence of water on the planet with space in any way. Scientists assumed that at structure of the planet Earth initially there were hydrogen layers which entered further chemical reaction with the oxygen which was in a land cloak at the initial stage of formation. Emergence of a huge amount of water on the planet was result of this interaction. Nevertheless, a part of scientists do not exclude participation of asteroids and comets in creation of water space in the huge territory of the earth. They assume that exactly thanks to the continuous attacks from great comets and asteroids which bore in themselves water reserves in the form of liquid, ice and steam there were huge water spaces filling the most part of the planet Earth. At all times people wanted to know how the mother Earth was formed. In spite of the fact that there is a mass of hypotheses, the question of origin of water on our planet still remains open.