LONDON — The world premiere of Mexican film director Alfonso Cuaron's “Gravity,” starring Sandra Bullock and George Clooney, will open the 70th Venice International Film Festival next month. Festival organizers said the 3D thriller starring Bullock and Clooney as astronauts cast adrift in space after disaster strikes their shuttle will kick off the festival on August 28. Bullock plays Dr. Ryan Stone, a brilliant medical engineer on her first shuttle mission, with Clooney as veteran astronaut Matt Kowalsky spiraling through the blackness of space. The 70th Venice International Film Festival, organized by La Biennale di Venezia, will be held on the Lido of Venice from August 28 to September 7. Veteran Italian director Bernardo Bertolucci, best known for his steamy 1972 movie “Last Tango in Paris”, will head the jury that decides the main awards at the annual cinema showcase, including the coveted Golden Lion prize for best picture. — Reuters