Related by context. Frequent words. (Click for all words.) 68 earthlings 56 aliens 53 Earth 53 extraterrestrials 51 Trekkies 51 outer space 51 Humans 50 beings 50 intergalactic 50 planet 50 interstellar 49 Martians 49 sentient 48 extraterrestrial 48 galactic 48 interplanetary 48 humankind 48 humans 48 creatures 47 mankind 47 alien 47 cosmic 46 cosmos 45 Earths 45 Autobots 45 Martian 45 Planet Earth 45 Klingons 45 alien invasion 44 critters 44 asteroid 44 Cylons 44 Red Planet 44 planets 44 orbiting 43 Tempel 1 43 planetary 42 Planets 42 Aliens 42 spacecraft 42 asteroids 42 Asteroids 42 Robots 42 spaceship 42 Starship Troopers 42 zombies 41 droids 41 lunar surface 41 human beings 41 galaxy 41 Decepticons 41 humanity 41 wormhole 41 interstellar space 41 invaders 41 Mars 41 comet 41 Daleks 41 neutrinos 40 flying saucers 40 Galactic 40 Apophis 40 undead 40 monsters 40 astronomers 40 robots 40 Solar System 40 sci fi 40 Na'vi 40 Sputnik 39 Galactica 39 distant galaxies 39 microbes 39 galaxies 39 universe 39 Saturn rings 39 starship 39 Saturn moon 39 moon 39 Apes 39 Carl Sagan 39 Stargate Universe 38 asteroid belt 38 Human beings 38 Deep Impact 38 Apollo astronauts 38 martian 38 creature 38 Satellites 38 Viewers 38 Androids 38 celestial bodies 38 celestial 38 solar flares 38 sea creatures 38 amateur astronomers 38 Mars Rover 38 comets 38 atoms 37 exoplanets 37 moons