The 36-year-old, who plays an astronaut in the upcoming space-based sci-fi horror film "Life" thinks there is a lot more in space that is still not explored.
"I believe there's so much yet to be explored," Gyllenhaal told nydailynews.com.
"I think absolutely, there is no doubt in my mind -- whether or not they're friendly or already here -- I think there's a lot left to explore," he added.
Directed by Daniel Espinosa, "Life" features a crew aboard the International Space Station, which has captured a sample from Mars, which backfires when the organism begins to grow stronger and smarter.
The film is slated to release in the US on Friday.
More Info: Life