A Space Odyssey changed the sci-fi genre forever, but it is not the genre’s only movie that has broken new ground.

Movies set in outer space often bend the rules of physics slightly, but they can be more powerful and immersive if they stick to scientific fact.

The final chapter of the Star Wars prequel trilogy, 'Revenge of the Sith', turns 20 this year, and Disney and Lucasfilm are bringing it back to theaters to celebrate.