Actor Matthew McConaughey and director Christopher Nolan debuted a new trailer for their film Interstellar during a surprise visit and their first ever appearance at the San Diego fan convention.

"Thought it would be a fun thing to come down and see what all the fuss is about," Nolan told the audience.

They surprised the fans with a first look at Interstellar, but neither of them offered any details about the highly anticipated space adventure, reported Variety.

"I can tell you a lot, but I'm not going to," McConaughey said at Thursday's Paramount Pictures panel.

So far, audiences have seen only short teasers and cryptic trailers for Interstellar.

Nolan explained that the movie will focus on space travel. "To be an astronaut was the highest ambition," he said.

"The idea to keep exploring space farther and farther, it fell off greatly. We are in a period of incredible technological change, but it's about what's in your pocket, your living room. I like the idea that we are on the cusp of a brand new era and we are travelling outwards more."

McConaughey expanded upon Nolan's hints and explained the concept more thoroughly.

"Cooper is a pilot, an engineer and a widowed pilot of two children where civilization is just sustaining," the Oscar-winner explained.

"There's food, clean water, but they don't need any explorers, no new bright ideas. Then something happens and the dream of being a pilot agains knocks on his door," he added.

The actor said that the movie pits his character's loyalty to the human race against his love for his family.

Although Nolan has a history of taking on ambitious projects, like the Dark Knight trilogy and Inception, the True Detective actor said, "By far, this is the most ambitious film that Christopher Nolan has ever directed."

The movie is set to premiere on 7 November and will also star Anne Hathaway, Jessica Chastain, Michael Caine and Casey Affleck.

Here is the trailer.