On the data on the speed of radioactive disintegration of atoms of various elements the time of existence of our planet is now determined as approximately 4,65 billion years. The age of the most ancient rocks, that are found on today, is 3,8 billion years. These rocks have kept prints of walls of the cells of the most ancient singlecell organisms. It means that these rocks originally began their growth in reservoirs with water, in which life should had existed long before the beginning of this growth, and this life should have taken an active part in biogeochemical processes. And it means that the primary hydrosphere with liquid water should have appear even earlier, not later than 4 billion years ago.

There could be two variants of occurrence of hydrosphere. One, which is standard now, degasation of melt magma, emissions of water as vapour by volcanos and through sources such as modern " black " or " white " smokers. But a lot depends on structure of primary substance, which has formed preEarth. Among primary elements, that formed our planet, besides substance such as meteoric should be a substance of cometic type, containing ice, metals and organics. So to say, the primary Earth had already enough of water as ice in the form of small parts or even of large inclusions. It is possible to assume the presence of gases, which enveloped particles, forming primary Earth. Therefore formation of primary hydrosphere and atmosphere can be divided into two stages. At first thermal front driven from the centre of the planet melt the ice, has released the molecules, which have "stuck” to the particles of gas, and has superseded this liquid and vapour substance on a surface. On the second stage an amplifying thermal flow began melting primary substance and releasing the chemically connected water and gases, so the process of degasation began.

The American L. Frank considers that the oceans have cometic origin, that they are the product of comet-looking bodies, entering the atmosphere of the Earth, and that this process proceeds till now. He finds the proof to this in the images of the Earth in ultra-violet area of a spectrum. The dark "holes”, found on the images, having the diameter of about 50 kms and duration of life about 3 minutes are interpeted by him as traces of intrusions of comet-looking bodies. L. Frank considers that "holes" are the congestions of particles of water and ice shielding a luminescence of a day time surface of an atmosphere. Primary Earth’s crust was thin and consisted of basalts, than resembled modern oceanic ones. Continental crust did not exist yet, and the ocean covered only a part of oceanic crust and was rather fine, but, probably, extensive. The hot gases quickly dissipated in the thin atmosphere, hot waters were quickly cooled and flew down in downturn. In a cold thin atmosphere water in the condition of vapour created clouds, which producted rain and snow, and it is possible, that ice coats were formed on the poles. After transformation of oceanic crust the period of growth of weight of ocean began again. It came nearer to modern condition and the rates of its growth strongly slowed down about 1 billion years ago.