Our natural satellite the Moon for nearly 70 million years had own atmosphere formed by volcanic gases. Experts have analysed data of researches on geology of the Moon and have come to a conclusion that later several hundreds of millions of years after education she has undergone the so-called period of late heavy bombing. The moon as well as all internal Solar system in a piece between 3,8 billion and was exposed to powerful bombing by fragments of the formed system 4,1 billion years ago.
On the Moon it has generated a series of eruptions of volcanoes which have made the surface of the satellite the infernal landscape filled with streams of a lava which has remained in the form of the lunar seas to this day. And during these terrible eruptions enough gases for creation of rather thick atmosphere which had to keep about 70 million years was thrown out. Though anyway she remained much less dense, than terrestrial. There wasn't enough gravitation of the Moon to hold the atmosphere long enough after the termination of volcanic activity. Though some connections or even some volumes of the stiffened gases could remain in a lunar subsoil.
In a series of researches studying of the samples brought from the Moon of Apollonami was used. These breeds have allowed to judge what gases existed on the Moon what their volume what was a chemical picture of the environment existing on the Moon was approximately. It corresponded to the periods of late bombing and volcanic activity.