Matthew McConaughey is starring in the upcoming Christopher Nolan film "Interstellar."  

In the sci-fi movie, the 44-year-old Oscar-winning actor plays Cooper, a widowed engineer who teams up with a group of researchers and astronauts on a daring scientific mission to save the Earth - through an extreme distance interstellar travel - after climate change takes its toll on it. Cooper, who has two children, and the rest of other explorers leave their families behind without knowing if they will ever see them again.

In a recent interview with New York Times, the "Dallas Buyers Club" actor recalled how he was approached by Nolan for the film.

"I was in New Orleans working on "True Detective," and my agent said, 'Christopher Nolan's got a new project coming out, and he's thinking of you - and some other people,'" he said. "I went to Chris's house, sat down for about three hours."

But Nolan and McConaughey did not even discuss the project during their initial meeting.

"I came away knowing nothing else about the film," the Uvalde, Texas-born actor told The Hollywood Reporter. "We talked about who we are as 43-year-old men, talked about who we are as [fathers], talked about our kids. We talked about some other films and work and just got really a sense of each other. And so when I walked out, I had a little bit of, 'OK, what was that?' I think he wanted to see who I was."

But when the New York Times asked what was it about the film that ultimately convinced him to take the role, McConaughey replied: "It had the things that I had loved about Chris's earlier films. That epic scope and size, which I think you get from him better than any director I know of. But also, this one seemed more intimate. It was a very human and a very simple question of a parent and a child, a father and a daughter. The most extreme circumstance of, "What would you do if ...?"

During a sat down interview with ABC News' David Muir, the "Magic Mike" star also revealed another reason why he decided to play Cooper.

When he was still pondering whether to take the role, the actor revealed that he thought of his eldest son Levi.

"He was into space and I would explain things in the solar system and how we got on the moon and all these things, and [he'd have] these young, wondrous eyes trying to, you know, work this out in his head," McConaughey said. "That was the main gut reason why I had to do this film."

"Insterstellar," which also stars Anne Hathaway and Jessica Chastain, opens in theaters on Nov. 7.