Even having read this whole thing, I am on some level surprised that the topic fills an entire book. But of course it does! This goes into the history of SETI a bit, what their goals have been in the past, and "new" SETI, as well as generally talking about alien intelligence -- what that might look like, how our conception of life and intelligence might be limited, how to communicate, etc, etc, etc! The topic is really interesting. The entire book is "well, it's highly unlikely, but why not? and we haven't found anything yet, but you never know!!" and despite the caveats and reminders that a lot of people are pessimistic about the whole thing, it reaffirmed my belief that the universe is too dang big to be completely empty but for us.

The only thing I didn't love was some of the opinionating that happened a few times. Stand-outs in the "what are you talking about, this is silly, stop it, go back to the science and stop giving me your Opinions About Non-Science Things" were: Why might a civilization travel in space?; Ramifications to religion if alien intelligence were discovered (religion in this case meaning Christianity); and What message should humans send out as a beacon (referencing the Pioneer plaque)? But those were momentary lapses in an otherwise good book.