On this day in 1610, Italian astronomer Galileo Galilei made his first observation of the four Galilean moons through his telescope: Ganymede, Callisto, Io and Europa, although he was not able to distinguish the latter two until the following day.
On this day in 1782, the first American commercial bank, the Bank of North America, opened.
On this day in 1959, the United States recognized the new Cuban government of Fidel Castro.
On this day in 1990, the interior of the Leaning Tower of Pisa was closed to the public for safety reasons.