He was 35 years old, scrunched into an 11-by-13 space capsule orbiting the moon with two other men on Christmas Eve 1968, when it happened. Anders had been assigned to shoot the pocked lunar surface.

Leonard S. Marcus brings the wonder of a 1968 snapshot to a new generation. “Earthrise,” taken by the Apollo 8 astronaut William Anders while in lunar orbit on Christmas Eve, 1968, at a ...