Related by context. Frequent words. (Click for all words.) 71 Milky Way galaxy 69 nebula 69 Milky Way 68 distant galaxy 67 quasar 66 galaxy 66 galaxies 64 supermassive black hole 63 gamma ray burst 63 planet orbiting 63 neutron star 61 supernova 61 brown dwarf 61 distant galaxies 60 pulsar 60 Betelgeuse 60 quasars 59 orbits 59 planets orbiting 58 nebulae 58 galaxy clusters 58 dwarf galaxies 57 redshift 57 supernovae 56 Saturn rings 56 neutron stars 56 rocky planets 56 planets 56 supermassive black holes 56 orbiting 55 astronomers 55 Solar System 55 brown dwarfs 54 gamma ray bursts 54 exoplanets 54 pulsars 54 corona 54 Iapetus 54 Cassiopeia 53 extrasolar planets 53 comet 53 gamma rays 52 Sedna 52 NGC 52 exoplanet 52 fainter 51 Pleiades 51 infrared wavelengths 51 Spitzer Space Telescope 51 Astronomers 51 Andromeda 51 nuclei 51 comets 51 Gliese 51 heliosphere 51 constellation 51 X ray Observatory 51 filaments 51 supernovas 50 luminosity 50 ellipse 50 cosmic microwave background 50 Enceladus 50 Kuiper Belt 49 starburst 49 galactic 49 atoms 49 asteroid belt 49 magnetosphere 48 cosmic rays 48 neutrino 48 elliptical orbit 48 sunspot 48 celestial objects 48 astrophysicists 48 Galaxies 48 interferometer 48 starlight 48 Cassini spacecraft 47 NASA Chandra 47 spectra 47 impactor 47 Uranus 47 moon Titan 47 positrons 47 celestial bodies 47 asteroids 47 orb 47 neutrinos 46 spherical 46 magnetic fields 46 asteroid 46 proton 46 particles 46 quark 46 NASA Cassini spacecraft 46 auroras 46 suns 46 comet Tempel 1 46 moons 45 gravitational waves