From the book's forward: Cosmos is a stand-alone solar system generator created in the finest traditions of science fiction. To paraphrase Arthur C Clarke, it isn't an accurate forecast, but rather an “exploration of possibilities”. From AlternityRPG.net: Cosmos totally replaces the Campaign Architecture chapter of the GMG. It attempts to make the sweeping discoveries in astronomy, made over the last decade, useful to the SF gamer; presenting new possibilities and a step-by-step guide to creating your own corner of the Universe. User Summary: This is not an official book, but a fan created book.