21 December in history.

1968

Apollo 8 heads for the Moon. Apollo 8 launched from Florida on course for the Moon. Its crew became the first people to travel to another world.

Wikipedia: Apollo 8

Photo: NASA/Bill Anders / Wikimedia Commons (Public domain)

More from 21 December

1. 1844

   The Rochdale Pioneers open their shop

   The Rochdale Pioneers opened their store in Rochdale, England, laying the foundations of the modern co-operative movement.

   Wikipedia: Rochdale Society of Equitable PioneersWikipedia: Cooperative

2. 

   1872

   HMS Challenger sets out to study the oceans

   HMS Challenger left Portsmouth on a scientific voyage that laid the foundations of oceanography.

   Wikipedia: Challenger expeditionWikipedia: HMS Challenger (1858)

   Photo: Unidentified engraver / Wikimedia Commons (Public domain)

3. 

   1879

   A Doll's House premieres

   Henrik Ibsen's play A Doll's House was first performed, at the Royal Danish Theatre, with Betty Hennings as Nora Helmer.

   Wikipedia: A Doll's HouseWikipedia: Henrik Ibsen

   Photo: Henrik Ibsen / Wikimedia Commons (Public domain)

4. 

   1937

   Snow White premieres

   Snow White and the Seven Dwarfs, the first full-length cel-animated feature film, premiered in Los Angeles.

   Wikipedia: Snow White and the Seven Dwarfs (film)

   Photo: Gustaf Tenggren / Wikimedia Commons (Public domain)

Moments chosen for discovery, creativity and courage. Each one links to a source where you can read more; photos are credited to their owners.