question astronauts roy thinnes ian hendry ask discover parallel world earth always hidden far side sun  cult science fiction melodrama released america journey far side sun plot film devised british writers gerry sylvia anderson creators tv shows ufo the thunderbirds space  exceedingly weird times betraying influence the twilight zone even stanley kubricks classic  space odyssey visual effects work derek meddings would also later work superman movie holds surprisingly well last three decades special effects advancements really exalted level kubrick film superb anticipate star warstype film overcome occasionally trite dialogue doppelganger good film good enough rank  consider undiscovered scifi gem