While preparing for the Damien Chazelle-directed film, First Man, the 37-year-old actor revealed he was "worried about saying the astronaut's famous line, "That's one small step for man, one giant leap for mankind."
"I was worried about it. It hung over me as it is the most famous life and a beautiful thing to say," Gosling said during an appearance on The Graham Norton Show set to air Friday, Oct. 5 on BBC America. "Neil didn't think about it ahead of time so I tried not to think about it too much."
The father of two also opened up about meeting with Armstrong's sons, Eric, 61, and Mark, 55, and making sure he did their father proud.
"Neil's sons wanted all the stories and context to shed new light on their father," the actor confessed. "It was the greatest challenge I have been part of and it was the biggest relief that, after they saw the film, they said, 'All our lives we have been asked what it is like to be the sons of the first man on the moon. Now we can say, 'Go and see the film.'"
ET was on the set of First Man where Gosling shared how much effort went into realistically recreating these space missions in missions in order to communicate the sheer cost of getting to the moon.
“I mean it's hard to communicate just how dangerous and how extreme these missions really were,” Gosling said. “Sitting in these really carefully reconstructed capsules having astronauts involved in those missions talking to me in my ear through the scenes. It was a very very surreal process, an opportunity I still can't believe I got to have.”