In this book P.S. Laplace - the famous French mathematician and astronomer (1749-1827) in a popular form sets out the content of his fundamental work - the five-volume Treatise on Celestial Mechanics and, based on the law of universal gravitation, explains all the observed motions of the planets and satellites of the solar system. At the end, he gives his cosmogonic hypothesis and gives an essay on the history of astronomy. The book is designed for a wide range of readers interested in the history of science, in particular astronomy and physics.