Interplanetary voyages 106 Human-alien encounters 48 Space flight 24 Exploration 23 Space warfare 20 Space ships 17 Time travel 16 mer ... Extraterrestrial beings 15 Science and civilization 12 Robots 11 Viajes interplanetarios 11 Astronauts 10 Enemies 7 Exploration of outer space 7 Interstellar travel 7 Video recordings for the hearing impaired 7 War 7 Women ship captains 7 Scott, Montgomery (Fictitious character) 6 Space colonies 6 Survival 6 Fugitives from justice 5 Life on other planets 5 Sulu, Hikaru (Fictitious character) 5 Enterprise (Imaginary space vehicle) 4 Good and evil 4 Space and time 4 Wormholes (Physics) 4 Espacio exterior 3 Feature films 3 mindre ...