Photograph courtesy NASA

July 20 is the 40th anniversary of humankind’s first steps on the moon. On July 16, 1969, the world watched as the Apollo 11 rocket Columbia lifted off from the Kennedy Space Center in Florida, carrying astronauts Neil Armstrong, Buzz Aldrin, and Michael Collins. The trip to the moon took three days, and on July 20, Neil Armstrong and Buzz Aldrin stepped off of the Eagle, Apollo 11′s lunar module. People back home on Earth watched the astronauts take their first steps on the moon, and heard Neil Armstrong say “That’s one small step for man, one giant leap for mankind.” The astronauts spent a total of 21 hours on the moon before the Eagle returned to the Columbia for the trip home.

The Apollo 11 crew safely returned to Earth on July 24, 1969. NASA plans to send another mission to the moon within the next decade.

Get the story behind the moon landing on National Geographic News.

Check out the Man and the Moon features on National Geographic Channel.

How much do you know about the moon? Quiz Your Noodle and find out!

Watch a video of Neil Armstrong and Buzz Aldrin on the moon.