Fifty years ago on Saturday, American astronauts Neil Armstrong and Buzz Aldrin became the first humans in history to set foot on the Moon, an event watched on television by half a billion people.
Six hours after touch down, Armstrong placed his left foot on the lunar surface, declaring: "That's one small step for man, one giant leap for mankind."
While Armstrong and Aldrin were on the surface, ex-fighter pilot Michael Collins remained in lunar orbit where he was in touch with ground control, providing them updates on his position.
Collins, now 88, has remained the more active of the surviving Apollo veterans, and frequently shares lyrical recollections of the mission.
A beautiful gorgeous tiny thing
Speaking at a Washington event on Thursday, he said that while the Moon itself was breathtaking seen up close, it was the view of Earth that has stayed with him and shaped his perspective.
"Out there was this little pea about the size of your thumbnail at arm's length: blue, white, very shiny, you get the blue of the oceans, white of the clouds, streaks of rust we call continents, such a beautiful gorgeous tiny thing, nestled into this black velvet of the rest of the universe.
"I said to Mission control, 'Hey, Houston, I've got the world in my window'."
NASA, the US agency responsible for space exploration, has been in overdrive for several weeks to mark the anniversary, with exhibits and events nationwide.
While US vice-president Mike Pence recently brought forward the deadline to return humans to the Moon from 2028 to 2024, President Donald Trump has publicly questioned NASA's plans for such a return, intended to test technology for Mars.