M45, The Pleiades: 410 Light Years
This is the closest Messier object, but the light you see now left the Pleiades more than 400 years ago. What was the world like then? The telescope was invented around 1600 in Holland; Galileo hadn't started playing around with lenses yet.
In England, Shakespeare was writing Hamlet. John Milton hadn't been born yet, and there was as yet no English settlement on the American mainland.