There are plenty of interesting technical details especially of the planets and as you would expect a very detailed description the Voyager spacecraft. The planets make up the bulk of the descriptions as the Voyagers fly-by each one. Scientists reactions to what they see as a result of the images transmitted back make the book even more readable and interesting. But, and it's a big but, the book (at least the copy I have) has two huge disappointments, one, the photographs throughout are poor, being displayed in dull grey and off white, two, the Colour Section titled as such is the biggest let down because none of the photos in this separate section are in colour, they are all in the same drab colour as the photos in the body of the book. I would have given the book 4 stars or possibly 5 but for the photos. I could not find any note in the book that explained why the Colour Section in particular does not contain colour photos. Maybe it something to do with this being a softback book i.e. if there is a hardback maybe that does have colour photos!!