Scientists consider that asteroids were a source of water on the Moon and in Earth . Astronomers analyzed isotope structure of samples of a deep cloak of the Moon, delivered by mission “Appolo” to the Earth, and came to a conclusion that water molecules in them and in a matter of Earth come from the same source, which most likely were asteroids. It is considered, that the Moon was formed as a result of collision of a protoplanetary body, with Earth “germ”. Collision led to emission of a matter of hot cloud of debris and proto-Earth in space, from which was created the Moon. This cataclysm was considered as the reason of why its subsoil and a surface are almost deprived of water. This hypothesis was called into question in February 2012, when scientists found unexpectedly high concentration of water in lunar magmatic breeds. Astronomers under the leadership of Erik Hauri from Carnegie’s Institute in Washington (USA) found one more argument against the classical theory of formation of the Moon, having analyzed isotope structure of breeds of its cloak. Hauri and his colleagues found water in magma inclusions in lunar soil in 2011, however information about its isotope structure demanded two additional years of researches. For this purpose scientists counted number of ions of a deuterium and protons in inclusions in samples of lunar soil with help of an ionic mass spectrometer and calculated their estimated proportion in hot cloud. It appeared that a deuterium in lunar breeds was a little and its share was identical to values, characteristic for Earth and the asteroids created in the first days after the birth of Solar system. According to scientists, this says that water of Earth and the Moon came from the same source, and the ratio of isotopes didn’t change from the moment of their formation. Collision of protoplanetary body and Earth had to lead to evaporation of its water-supplies and to serious changes in isotope structure that didn’t occur. It calls into more questions the classical theory of formation of the moon.