Related by context. Frequent words. (Click for all words.) 69 distant galaxy 64 gamma ray burst 64 galaxy cluster 62 planet orbiting 61 Milky Way Galaxy 61 comet 60 spiral galaxy 60 asteroid 60 distant galaxies 60 rocky planets 59 supernova 59 nebula 59 Betelgeuse 58 brown dwarf 58 Sedna 58 planets 58 planets orbiting 58 galaxies 58 galaxy 58 gamma ray bursts 58 XMM Newton 57 exoplanet 57 asteroids 57 Milky Way 57 quasar 56 supermassive black hole 56 quasars 56 Milky Way galaxy 56 extrasolar planets 56 brown dwarfs 56 Saturn rings 56 nebulae 56 celestial objects 55 orbits 55 Solar System 55 infrared wavelengths 55 astronomers 55 unaided eye 55 galaxy clusters 55 celestial bodies 55 pulsar 55 telescope 55 exoplanets 55 globular clusters 55 supernovae 54 redshift 54 meteor shower 54 gravitational waves 54 spiral galaxies 54 interstellar dust 53 neutron star 53 Saturn moon 53 dwarf galaxies 53 auroras 53 Spitzer Space Telescope 53 comets 52 Halley Comet 52 meteor 52 aurora 52 solar flares 52 moon Titan 52 neutrino 52 impactor 52 NASA Cassini spacecraft 51 starlight 51 moons 51 Astronomers 51 THEMIS 51 telescopes 51 supernovas 51 Iapetus 50 cometary 50 Enceladus 50 pulsars 50 cosmic ray 50 orbiting 50 cosmic rays 50 atomic particles 50 meteors 50 gamma rays 50 outer planets 50 elliptical orbit 50 orb 50 Phobos 50 spacetime 49 heliosphere 49 Apophis 49 Hubble Telescope 49 neutron stars 49 Space Telescope 49 flyby 49 Cassiopeia 49 astrophysical 49 cosmos 49 MESSENGER 49 supermassive black holes 49 Kuiper Belt 49 Alpha Centauri 49 Pleiades 49 celestial 49 Very Large Telescope