Related by context. Frequent words. (Click for all words.) 61 Halley Comet 60 HD #b [002] 60 Eta Carinae 59 Orion Nebula 58 distant galaxy 57 comet 57 extrasolar planets 56 exoplanets 56 planets orbiting 55 moons 55 outer planets 55 GRBs 55 nebulae 54 supernova explosion 54 extrasolar planet 54 comets 53 Lutetia 53 XMM Newton 53 Saturn rings 53 Space Telescope 53 Mars 53 gamma ray burst 53 Saturn moons 53 Milky Way Galaxy 53 unaided eye 53 planets 52 quasars 52 planet orbiting 52 galaxy cluster 52 globular clusters 52 supernova 52 Sedna 52 dwarf galaxy 52 distant galaxies 52 Uranus 52 Perseids 52 Solar System 52 Betelgeuse 52 spiral galaxies 52 NASA Cassini spacecraft 52 Enceladus 51 infrared wavelengths 51 supernovas 51 Saturn moon 51 supernovae 51 Orbiting 51 supernova explosions 51 spiral galaxy 51 orbits 51 ringed planet 51 exoplanet 51 brown dwarf 51 super Earths 51 dwarf galaxies 51 Milky Way galaxy 50 comet nucleus 50 Milky Way 50 elliptical galaxies 50 brown dwarfs 50 terrestrial planets 50 celestial bodies 49 rocky planets 49 nebula 49 gamma ray bursts 49 gravitational waves 49 Spitzer Space Telescope 49 orbited 49 celestial objects 49 Gliese 49 quasar 49 galaxies 49 sunspots 49 comet Wild 49 occultation 48 dust devils 48 astronomers 48 pulsars 48 Cassini 48 redshift 48 Ursa Major 48 auroras 48 ejecta 48 Pleiades 48 meteor showers 47 cosmic microwave background 47 Phobos 47 sunspot 47 perigee 47 WMAP 47 galaxy 47 Martian surface 47 Itokawa 47 Hubble 47 NASA Chandra 47 orbiting 47 flybys 47 celestial 47 astrophysical 47 solar eclipses 47 Cassini spacecraft 47 neutron star