Related by context. Frequent words. (Click for all words.) 75 rocky planets 72 brown dwarfs 71 exoplanets 70 planets orbiting 69 planets 68 extrasolar planets 67 exoplanet 66 brown dwarf 65 globular clusters 64 habitable zone 64 planet orbiting 64 dwarf galaxies 60 galaxy clusters 60 galaxies 60 quasars 59 UB# [003] 59 redshift 59 supernovae 59 supermassive black holes 58 Milky Way Galaxy 58 neutron star 58 asteroids 58 comets 58 dwarf planets 58 distant galaxy 58 galaxy cluster 58 neutron stars 57 supernovas 57 pulsars 57 Sedna 57 Earths 57 supernova explosion 57 Gliese 57 spiral galaxies 56 orbits 56 quasar 56 Milky Way galaxy 56 Astronomers 56 astronomers 56 moons 56 Kuiper Belt 55 organic molecules 55 distant galaxies 55 gamma ray bursts 54 Milky Way 54 outer planets 54 Betelgeuse 54 asteroid 53 XMM Newton 53 supernova 53 abundances 53 gamma ray burst 53 supermassive black hole 53 planetary 53 Saturn moon 53 cosmologists 53 Spitzer Space Telescope 53 Enceladus 52 suns 52 olivine 52 nebulae 51 nuclei 51 NEOs 51 neutrinos 51 Saturn rings 51 fainter 51 deuterium 51 pulsar 51 infrared wavelengths 51 unaided eye 51 galaxy 51 orbiting 51 astrophysicists 50 positrons 50 moon Titan 50 comet 50 NASA Chandra 50 X ray Observatory 50 neutrino 50 cyanobacteria 50 earths 50 sunspot 49 northern latitudes 49 gravitational waves 49 nebula 49 ringed planet 49 asteroid belt 49 spiral galaxy 49 Higgs boson 49 celestial objects 49 cosmic microwave background 49 habitability 49 hydrothermal vents 49 dwarf planet 48 hydrogen atoms 48 single celled 48 neutrons 48 interstellar dust 48 atomic nuclei 48 atoms 48 Iapetus