Alfonso Cuaron’s “Gravity” is expected to cross the $500 million mark globally on Saturday, becoming one of the most successful sci-fi movies of all-time and the biggest box office hit of both Sandra Bullock’s and George Clooney’s careers.

The 3D sci-fi smash, which is being tipped for a run at the Oscars, has earned a boffo $235.9 million domestically and over $261 million overseas. Last month, “Gravity” became the highest-grossing live-action feature in October history with over $400 million worldwide.

Bullock’s previous highest-grossing film was “Speed” ($350.2 million) while Clooney’s benchmark was “Ocean’s Eleven” ($450.6 million).

“We know what we have here,” Warner Bros distribution president Dan Fellman recently told Variety. “This is a phenomenon where people are asking friends and family not only if they’ve seen the film, but where.”

The $100 million space odyssey largely benefitted from premium 3D and Imax ticket prices as well as repeat viewings.

Greg Foster, chairman of Imax, called “Gravity” an “early Christmas present” for studios and theatrical exhibitors. “The habit of going to the movies is created when you have a great experience,” he said.

Co-financed by Warner Bros. and RatPac Dune Entertainment, “Gravity” is expected to remain in theaters through Thanksgiving.