Extraterrestrial beings 6 Gordon, Flash (Fictitious character) 3 Space travelers 3 Space warfare 3 Human-alien encounters 2 Artificial intelligence 1 Astronauts 1 more ... Cannibalism 1 Clowns 1 Computers 1 Ecology 1 Environmental aspects 1 Environmental ethics 1 Exploration 1 HAL (Fictitious character) 1 Human-computer interaction 1 Indigenous peoples 1 Life on other planets 1 Mercenary troops 1 Mineral industries 1 Outer space 1 Pandora (Imaginary place) 1 Space colonies 1 Space flight to Jupiter 1 Space vehicles 1 Teenagers 1 Twenty-first century 1 Video recordings for the hearing impaired 1 less ...