Astronomical predictions for the 23rd century
In the early 23rd century Pluto will switch ranking with Neptune and become the 8th planet from the sun.
August 28, 2287 - Mars and Earth come very close, the closest since August 27, 2003.
Science Fiction set in the 23rd century
Babylon 5, a TV-series set in the mid 23rd century
Satellite Night trilogy, by Nick Pollotta
The Glass Bead Game, a novel by Hermann Hesse
The Fortune Call, a novel by Raphael Carter
Zardoz, a movie in a post-apocalyptic 23rd century
Star Trek: The Original Series
Star Trek: The Animated Series
Starcraft, a computer game set in the late 23rd century