This is a book about our species’ “zest to explore and exploit.” Although the subtitle is “A Vision of the Human Future in Space,” there is also substantial attention given to our history as wanderers.

One unexpected aspect of the discussion is the politics of crewed space programs, including a discussion of the Apollo program’s Cold War origins (ch. 13). This was also the first I had heard of George H.W. Bush’s plan, announced in 1989, to put humans on Mars by 2019. SpaceX was founded 13 years after the rollout of Bush’s plan, but may miss its target date by only 6 years. (Musk has predicted that humans will arrive on Mars by 2025, but then again he is famous for overly optimistic timetables.)

There are also brief asides that, read 22 years after Pale Blue Dot was first published, seem almost like predictions. For example, Sagan mentions the role of profit as a motive for space exploration (p. 217). He also describes how the advent of artificial intelligence could cause use to think differently about our own consciousness (p. 10).

Without giving away any spoilers, chapter 17 contains the seed of the plot in Neal Stephenson’s Seveneves, while chapters 21 and 22 contain ideas about long-term human survival that are relevant as well. Besides Stephenson’s novel, other books to read alongside this one are The Clock of the Long Now, Apollo 13, and the Elon Musk biography.