First trailer for Alfonso Cuaron's 'Gravity' starring George Clooney and Sandra Bullock

When Alfonso Cuaron first began putting the pieces together for his ambitious new sci-fi film, Gravity, it looked a lot different than it does now. Initially Robert Downey Jr. and Angelina Jolie were set to star, but that fell through and a virtual who's who of Hollywood actresses passed through the female lead, among those were Natalie Portman, Naomi Watts, Marion Cotillard, and Scarlett Johansson. Ultimately, Sandra Bullock won the role, and George Clooney slid in to be her co-star, making for a powerful pair.

After we were treated to a sneak peek of the teaser a couple of days ago, the first full trailer for Gravity has been released, and it certainly looks like the sort of ambitious project one would expect from the director of the classic Children of Men. Reportedly opening with an incredible, 17-minute tracking shot,  you don't see any hint of that here, but the spectacle of it all is certainly well on display. The film follows two astronauts who must make the dangerous journey back to Earth when their crew is killed and their shuttle destroyed during a space walk.

So what do you think? Are you impressed? Should we start looking at Gravity as a potential Oscar threat? Look for it to hit theaters on October 4th.