Trivia

The exterior Martian scenes were shot at a slower speed to simulate Mars' gravity, which is 38% of Earth's gravity. Therefore, anything on the surface of Mars needed to appear lighter and have a slight bounce to it. However, the frame rate that was desired would not allow the cameras to run in sync. To negate this, the film was shot at 48 frame per second during exterior scenes, which was then sped up to the standard 24 frame per second. This meant that much audio had to be re-recorded in post. As a result of this, syncing up audio with Mark's lips filmed at a slower frame rate would have been impossible. Ridley Scott chose to have Mark "narrate" the scenes instead of having him talk in the suit to avoid this problem. See more