As part of the process his beams of light rebound on the nucleus of passing comets which determine where and when the time traveller will end up.
Halley's Comet | Cell nucleus | nucleus | comet | Comet | de Havilland Comet | Atomic nucleus | The Blue Comet | Captain Comet | Sozin's Comet: The Final Battle | Silver Comet Trail | Nucleus | Geykido Comet Records | De Havilland Comet | Comet Shoemaker–Levy 9 | Comet in Moominland | cell nucleus | atomic nucleus | Time of the Comet | The Comet Song | Superior salivary nucleus | Silver City Comet | PS ''Comet'' | PS Comet | nucleus (biology) | Night of the Comet | Moomins and the Comet Chase | Lateral reticular nucleus | Inferior salivatory nucleus | Great Comet of 1823 |