January 25, 1905
A routine inspection in the Premier Mine in Pretoria, South Africa, reveals the world’s largest diamond at 3,106 carats (1.33 pounds!).
January 28, 1986
The Challenger, carrying Christa McAuliffe, who was to be the first teacher to travel to space, explodes 73 seconds after takeoff.
January 29, 1936
The U.S. Baseball Hall of Fame elects its first members, including Ty Cobb, Babe Ruth, and Honus Wagner.