Theories of the formation of the Earth-Moon system allow us to undertsand not only our historical relationship to science and observation but also how we have perceived ourselves in the context of the vastness of the universe. In this paper the author discusses her work Soft Moon -a computer-generated film that explores the mutual attraction of two planetary spheres, with reference to the story of the same name and other works by Italo Calvino and by Stanislaw Lem. The development of the film is intercontextualized with a series of ancient and modern historical theories of the formation of the Earth-Moon system.