Related by context. Frequent words. (Click for all words.) 54 Neil deGrasse Tyson 53 SETI Institute 50 Astrophysicist 50 extraterrestrial 50 Phil Plait 50 habitable planets 49 NASA Kepler 49 alien civilizations 49 astronomer 48 astrobiologists 48 Gliese #g 47 extrasolar planets 47 astrophysicist 47 Michael Shermer 46 cosmologist 46 astrobiologist 46 Carl Sagan 46 planetary scientist 46 SETI 46 extrasolar planet 45 extraterrestrials 45 Stephen Hawking 45 habitable planet 45 exoplanet 45 astrobiology 44 Astronomer 44 interplanetary spacecraft 44 Hawking 44 cosmologists 44 distant galaxy 44 Kepler 44 theoretical physicist 43 Lowell Observatory 43 astronomical objects 43 James Lovelock 43 extra terrestrials 43 earthlings 42 planets orbiting 42 pulsars 42 Professor Hawking 42 Kurzweil 42 planets 42 planet 42 rocky planets 42 astronomy 42 Earthlings 42 COROT 42 ETs 42 Lick Observatory 42 Tyche 42 Richard Feynman 41 Sedna 41 Cassini Huygens 41 HD #b [002] 41 planetary sciences 41 Alpha Centauri 41 SETI @ home 41 optical telescopes 41 universe 41 Credit NASA JPL 41 Shostak 41 alien spacecraft 41 stargazer 41 exoplanets 41 parapsychology 41 UFOs 40 gravitational wave 40 Saturn moons 40 Mathematician 40 Happy bargain hunting 40 Cancri 40 celestial objects 40 astronomers 40 Professor Stephen Hawking 40 Cassini imaging 40 Mars rovers 40 astrophysicists 40 LSST 40 NASA JPL 40 physicist 40 Cosmology 40 Space.com 40 Ray Kurzweil 40 Michael A'Hearn 40 Physicist 40 particle physicists 40 magnetar 40 unaided eye 40 debunker 39 planetary science 39 Dark Matter 39 planetary 39 Hubble 39 Gamma ray bursts 39 gamma ray burst 39 terrestrial planets 39 distant galaxies 39 Borucki 39 Milky Way galaxy 39 Peter Diamandis 39 moon Europa