It was 45 years ago that one man made a giant leap for mankind.

Neil Armstrong set foot on the moon 45 years ago, becoming the first man to do so. Jim Gray sat down with Gene Cernan, the last astronaut to walk on the moon, who reflected on the historic day.

“And there we were, 45 years ago, on the 20th of July, 1969, an American made the impossible possible, when Neil made those first steps, that one small step for man,” Cernan said.

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He asked: What’s more expressive of American exceptionalism than Armstrong’s first steps on the moon?

Cernan also discussed his experience walking on the moon, saying it’s hard to truly describe what it’s like.

Watch the interview above.