Related by context. Frequent words. (Click for all words.) 80 Milky Way 78 galaxies 77 galaxy 72 distant galaxies 71 supermassive black hole 70 planets 69 nebula 69 quasars 69 supermassive black holes 68 neutron star 67 rocky planets 67 neutron stars 67 galaxy clusters 66 quasar 66 supernovae 65 planets orbiting 65 extrasolar planets 65 exoplanets 64 Solar System 63 Kuiper Belt 63 brown dwarfs 63 pulsar 63 brown dwarf 63 supernova 62 comets 62 exoplanet 61 gamma ray burst 60 pulsars 60 supernovas 60 redshift 60 galactic 60 comet 59 asteroid belt 59 astronomers 59 orbits 58 gamma ray bursts 58 Spitzer Space Telescope 58 Saturn rings 57 cosmic microwave background 56 gravitational waves 56 Enceladus 55 fainter 55 Astronomers 55 Sedna 55 magnetosphere 55 universe 54 planetary 54 asteroids 54 neutrino 54 interstellar space 54 Galaxies 54 infrared wavelengths 53 gamma rays 53 orbiting 53 neutrinos 53 moons 53 cosmos 53 subatomic particles 53 Gliese 52 asteroid 52 atoms 51 celestial bodies 51 NASA Chandra 51 celestial objects 51 cosmic rays 51 suns 51 corona 51 Uranus 50 sunspot 50 planet 50 astrophysicists 50 moon Titan 50 Harvard Smithsonian 50 magnetic fields 49 Tempel 1 49 gamma ray 49 habitable zone 49 Earths 49 nuclei 49 neutrons 49 Saturn moon 49 Astrophysical Journal 49 sunspots 48 general relativity 48 Martian atmosphere 48 telescopes 48 spectroscopic 48 Andromeda 48 cosmic 47 comet Tempel 1 47 organic molecules 47 starlight 47 photons 46 solar flares 46 astronomer 46 telescope 46 Pleiades 46 equatorial 46 elliptical orbit 46 auroras 46 filaments