National Moon Day is marked annually on July 20 to commemorate the landmark mission when man first walked on the moon.

In 1969, Apollo 11 carried the first humans to the moon. Neil Armstrong was the first person to step onto the lunar surface. He spent two and a half hours outside the spacecraft. Buzz Aldrin soon followed, stepping onto the lunar surface. After joining Armstrong, the two men collected 47.5 pounds of lunar material. The pilot, Michael Collins, was in the orbit alone until Armstrong and Aldrin returned.

Here are some quotes by Armstrong, collected by Brainy Quote, to share on this day:

1. "I believe every human has a finite number of heartbeats. I don't intend to waste any of mine."

2. "Mystery creates wonder and wonder is the basis of man's desire to understand."

3. "That's one small step for a man, one giant leap for mankind."

4. "In much of society, research means to investigate something you do not know or understand."

5. "I guess we all like to be recognized not for one piece of fireworks, but for the ledger of our daily work."

6. "Here men from the planet Earth first set foot upon the Moon. July 1969 AD. We came in peace for all mankind."

7. "Science has not yet mastered prophecy. We predict too much for the next year and yet far too little for the next 10."

8. "Well, I think we tried very hard not to be overconfident, because when you get overconfident, that's when something snaps up and bites you."

9. "The one thing I regret was that my work required an enormous amount of my time, and a lot of travel."

10. "I thought the attractions of being an astronaut were actually, not so much the Moon, but flying in a completely new medium."

China hopes to have a crewed space station by 2022 and eventually send humans to the Moon
China hopes to have a crewed space station by 2022 and eventually send humans to the Moon AFP / Laurent EMMANUEL