Related by context. Frequent words. (Click for all words.) 72 nebula 72 distant galaxy 70 galaxies 69 distant galaxies 68 spiral galaxy 68 quasars 68 Milky Way galaxy 67 Milky Way 66 nebulae 66 quasar 66 planets 65 planets orbiting 65 extrasolar planets 64 brown dwarfs 64 gamma ray burst 64 Betelgeuse 64 galaxy 63 supernovae 63 Spitzer Space Telescope 63 gamma ray bursts 62 planet orbiting 62 exoplanets 62 rocky planets 62 supernovas 62 brown dwarf 62 exoplanet 61 supernova 61 Solar System 61 celestial objects 61 galaxy clusters 61 supermassive black hole 60 comets 60 astronomers 59 pulsars 59 comet 59 Saturn rings 59 dwarf galaxies 59 infrared wavelengths 59 redshift 58 Kuiper Belt 58 auroras 57 gamma rays 57 neutron star 57 neutron stars 57 pulsar 57 fainter 57 moons 56 X ray Observatory 56 Pleiades 56 Astronomers 56 NASA Chandra 55 Space Telescope 55 corona 55 aurora 55 Enceladus 55 supermassive black holes 55 Sedna 55 NASA Cassini spacecraft 54 asteroids 54 cosmic microwave background 54 solar flares 54 Gliese 54 Very Large Telescope 54 orbits 53 constellations 53 sunspot 53 Perseids 53 sunspots 53 starburst 53 celestial bodies 53 cosmic rays 53 suns 52 Iapetus 52 Saturn moon 52 magnetosphere 52 luminosity 52 Cassiopeia 52 meteor shower 52 telescope 52 Galaxies 51 habitable zone 51 Cassini spacecraft 51 WMAP 51 NGC 51 orbiting 50 meteors 50 spectroscopic 50 telescopes 50 astrophysical 50 Uranus 50 moon Titan 50 infrared radiation 50 Andromeda 50 THEMIS 50 gamma ray 50 Cassini 50 GRB 50 neutrino 49 spectra 49 asteroid 49 starlight