United Kingdom, Feb. 9 -- Steven Spielberg is convinced "there is life off this planet".

The 79-year-old director has helmed a new UFO movie called Disclosure Day, and Spielberg has opened up about his own long-term fascination with the prospect of there being alien life.

In a behind-the-scenes video shared by Universal Pictures, Spielberg says: "I've always been fascinated with things that cannot be explained, and I've made a lot of movies about things that could not be explained, from sharks to saucers.

"When I was just a little kid I remember developing a real curiosity about the sky at night and what's happening up there, and also not the possibility but the guarantee that there is life off this planet."

Spielberg thinks the publi...