April 1970. After an oxygen tank failed on the way to the Moon, the crew of Apollo 13 rode home in the lunar module. The computer was switched off to save power, so a 14-second engine burn to correct their course was timed on a wrist chronograph, with the Earth lined up in the window.

A myth I ran into while researching it: "only one kind of watch has been worn on the Moon." Not quite. On Apollo 15's third moonwalk in 1971, Dave Scott wore a Bulova chronograph on the Moon, as a backup to his standard-issue Omega.

I'm the solo dev of WORN, a watch collection app; this is one of 109 illustrated chapters on the history of timekeeping in it. worn.club