LOS ANGELES — The Sandra Bullock-George Clooney space drama “Gravity” rocketed to the top of the box office and into industry record books during its opening weekend.

The Warner Bros. adventure debuted with $55.5 million in North American ticket sales, according to studio estimates Sunday – the biggest October opening ever and the biggest openings for Bullock and Clooney. The film also dominated the international box office, adding another $27.4 million.

The film is set almost entirely in space and explores challenges faced by two astronauts during a spacewalk.Last week’s top movie, Sony’s “Cloudy with a Chance of Meatballs 2,” rolled into second place with $21.5 million. R-rated fare rounded out the top six. Twentieth Century Fox’s “Runner Runner,” starring Ben Affleck and Justin Timberlake, opened in third place with $7.6 million.

Warner Bros.’ “Prisoners,” starring Hugh Jackman and Jake Gyllenhaal, locked onto the fourth spot. Universal’s racing tale “Rush,” starring Chris Hemsworth, drove into fifth place, followed by “Don Jon,” Joseph Gordon-Levitt’s directorial debut about a porn addict looking for love.