Much like the actual mission at the heart of the film, the casting for Gravity went through a lot of bumps in the road. Alfonso Cuarón's visually stunning Oscar darling almost looked a lot different than the Sandra Bullock-George Clooney pairing, with several other major actors vying for the two leads. The rumor mill originally claimed Johansson had signed to play the role of stranded astronaut Ryan Stone, but it turned out to be getting a bit ahead of itself.
Originally, Clooney's role of Matt Kowalski was going to be played by Robert Downey Jr. That means we could have had an interesting little MCU crossover, had Johansson been cast as originally reported. Apparently, Johansson wasn't even the first choice for the film, though. It was originally Angelina Jolie's role, but she left the project, paving the way for Johansson. Soon, Blake Lively's name started popping up as ScarJo's competition.
We don't really know exactly how far along any of this casting went but, obviously, not one of the trio of Downey, Johansson or Lively was cast in Gravity. It would have been interesting to see Johansson's take on the character, but Bullock's Oscar-nominated performance was excellent.
