Gravity topped the box office for the second week in a row.

The Sandra Bullock and George Clooney sci-fi film brought in about $44 million this weekend. In its opening weekend starting Oct. 4, Gravity grossed $55 million. It became the best October opening ever. And, the movie's domestic sales have now surpassed the $100 million mark.

PHOTOS: Sandra Bullock & George Clooney At Gravity Premiere

The film focuses on Clooney's character, a veteran astronaut, who becomes stranded in space along with a highly skilled technician played by Bullock. The two characters, who are seen floating through space throughout the film, struggle to get back to Earth. To prepare for her role in the movie Bullock said she worked with professional astronauts.

"They were incredibly helpful, and they gave me an inside visual as to why they do what they do," she told reporters at a press conference held for the film. "It was the craziest, most bizarre, and most challenging shoot I've ever done."

Bullock also previously explained the reasons she believes this movie is worth watching.

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"I think there are so many elements to this film that are going to drive the story," she told Nerdist. "You have the journey, you have where they came from, you have the sound of everyone's breath, and losing their air. Is it the end of their life? What are the choices that they're going to make?"

Coming in second at the box office was Tom Hanks' Captain Phillips. The movie grossed $26 million in its opening weekend. In the film, the 57-year-old plays a cargo ship captain who is held captive by Somali pirates.

Weekend Box Office, according to Box Office Mojo.

1. Gravity: $44.3 million

2. Captain Phillips: $26 million

3. Cloudy With a Chance of Meatballs 2: $14.2 million

4. Machete Kills: $3.79 million

5. Runner Runner: $3.72 million

6. Prisoners: $3.66 million

7. Insidious Chapter 2: $2.6 million

8. Rush: $2.36 million

9. Don Jon: $2.34 million

10 Enough Said: $2 million

Tags: Sandra Bullock George Clooney tom hanks