It was 43 years ago on Friday that Neil Armstrong and Edwin "Buzz" Aldrin, two members of the Apollo 11 crew, became the first humans to set foot on the moon.
"That's one small step for a man, one giant leap for mankind."
The Saturn V rocket carrying the Apollo 11 crew had blasted off from Florida about 109 hours earlier.
The two astronauts spent just over 21 hours on the moon before returning to the orbiting Columbia module to begin their journey back to Earth. They brought with them almost 50 pounds of geological samples, according to the Lunar and Planetary Institute.
The two men, along with Command Module Pilot Michael Collins, splashed down safely in the Pacific Ocean on July 24, 1969.
It was the realization of a goal that President John F. Kennedy had set eight years earlier in a speech to Congress:
First, I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish.
It's been almost 40 years since a person last walked on the moon, and NASA now has its sights set on Mars. Next month, the Curiosity rover, which is about the size of a small SUV, is expected to land there, and NASA is developing a heavy lift rocket that it hopes will one day take humans to the red planet.
LOOK: Pictures from Apollo 11: