Matthew McConaughey stars in Christopher Nolan’s highly-anticipated upcoming sccience-fiction film Interstellar, but in a recent interview, the Academy Award winner admitted that he almost didn’t take the film’s leading role. When McConaughey and his fellow co-stars sat down with ABC News’ David Muir, they each revealed the unique reasons they joined what is already being considered an Oscar-contender film.

Interstellar centers on a team of explorers who are tasked with traveling to another galaxy in search of another planet for humans to live on, because Earth’s climate change is making it incapable of sustaining life. McConaughey stars as a father and former astrounat, and the 44-year-old actor says that his son Levi’s love for space is what eventually convinced him that he had to take the role.

“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,” said McConaughey. “That was the main gut reason why I had to do this film.”

The emotion of the script for the film, which was originally written by his brother Johnathan, was what director Christopher Nolan said motivated him to take on the project.

“My brother’s original script has this amazing set of characters at the heart of it. This family who’s sort of tested in this extraordinary way,” he said. “And that’s the thing that I most related to in the film.”

In the ABC News interview, Oscar nominee and Interstellar co-star Jessica Chastain gave her own reasons for joining the film – the relevant subject matter and her hope that it will inspire younger generations.

“If you look at this film and you look at where we are right now in the world — and the climate changes that’s happening … You have to push forward and evoke some kind of positive change in your life, in the world,” said Chastain. “The idea that there could be a 7-year-old kid and it inspires her or him to want to go into space and explore space, I think that’s incredible.”