Disclaimer - I consider Carl Sagan an outstanding scientist, visionary human, and personal hero. I was always going to like this book!
So I'll start with minor quibbles that I think Mr Sagan would approve of. It's a book from the 90s, some of the science and history is of course dated to that time. In some aspects we are behind his optimistic curve, others ahead in surprising ways - the commercialisation of space exploration for example.
However, the tempered sense of awe and hope that pervades his absolutely beautiful prose outshines these minor points. What an exquisite writer to add to everything else. The book will be worth reading in a hundred years for both content and form.
Content ranges from excellent arguments that all children should study against the central place of humans in the universe, to how our species may expand out of the solar system. Thoughtful, realistic, illuminating, wonderous, funny, yet acerbic to human stupidity and shortsighted government spending!
Contains the famous pale blue dot paragraph, I'm clearly not alone in judging it among the most beautiful and meaningful passages ever assembled. There are others in there too.