What planet is Discovery One traveling to in "2001: A Space Odyssey"?

The answer is: Jupiter

Jupiter stars as Discovery One's destination in "2001: A Space Odyssey," though that wasn't always the plan. Arthur C. Clarke's novel sent the ship to Saturn, but Kubrick ran into a wall during film production. His effects team couldn't create convincing Saturn rings with 1968's technology.

The Saturn scenes proved impossible to pull off with the practical effects available at the time. After several failed attempts, Kubrick made the decision during to switch to Jupiter. The special effects team, led by Douglas Trumbull, created Jupiter's swirling atmosphere and used a technique called "slit-scan photography," where multiple exposures of liquid chemicals and paints created the psychedelic star gate sequence. These innovations later influenced films like "Star Wars" and "Close Encounters of the Third Kind."

Clarke eventually embraced Kubrick's vision when writing the sequel novel "2010: Odyssey Two," making Jupiter the canonical destination and bringing the literary and film universes back into alignment. Trumbull would finally tackle Saturn just four years later in his 1972 directorial debut "Silent Running," where he successfully created the ringed planet that had eluded him on "2001."