Michael Collins—who was bumped from Apollo 8 due to a medical issue and of course ended up flying Apollo 11 instead—became increasingly convinced with time that it was Apollo 8, more so than 11, that represented the true landmark in human history.

Apollo 11 was when we first arrived somewhere new, yes, but it was Apollo 8 when we first dared to venture out into the dark. For the first time we surrendered the ability to quickly return to Earth in a matter of minutes or low-single-digit hours.

Collins’ autobiography Carrying the Fire is easily the best of the astronaut memoirs, and is written purely by Collins without a ghostwriter. It wasn’t one of the talents NASA was looking for, but I’m glad they sent an excellent writer to the moon.