Instruct: Classify a given review as either positive or negative.
Query: A great book for fans and would be authors.

The book is not just about aliens and alien societies. It also deals with making proper stars and planets and what alien science might be like. Could of used more details on the subject of planet building, but there are other works that get into the nuts-and-bolts of that subject. This book touches lightly on alien culture, view points and history, not just the science of building an alien creature. Also, some of it might be outdated with our increasing knowledge of other planets and solar systems. It looks more and more like our idea of planet forming and how systems form might be slightly incorrect (if not out right wrong). That is why I held back a star.