Related by context. Frequent words. (Click for all words.) 84 extrasolar planets 78 exoplanet 76 planets orbiting 76 planets 71 brown dwarfs 70 rocky planets 68 brown dwarf 67 supernovae 66 quasars 66 galaxies 65 distant galaxies 65 Milky Way galaxy 65 pulsars 64 gamma ray burst 64 gamma ray bursts 64 galaxy clusters 63 supernova 63 Gliese 63 astronomers 62 comets 62 Sedna 62 pulsar 62 quasar 62 supernovas 61 neutron star 61 asteroids 61 redshift 60 galaxy 60 habitable zone 60 Milky Way 59 Kuiper Belt 59 nebula 59 neutron stars 58 supermassive black hole 58 gravitational waves 58 neutrinos 58 infrared wavelengths 58 Saturn rings 57 Astronomers 57 Enceladus 57 celestial objects 57 supermassive black holes 57 comet 57 Spitzer Space Telescope 56 neutrino 56 Solar System 56 moons 56 orbits 55 asteroid 55 Earths 55 celestial bodies 55 astrophysicists 54 Saturn moon 54 cosmic rays 54 UB# [003] 54 planetary 54 cosmologists 53 infrared radiation 53 cosmic microwave background 53 gamma rays 53 orbiting 53 atoms 53 Pluto 53 NASA Chandra 53 subatomic particles 52 Kepler 52 asteroid belt 52 quark 52 Uranus 52 neutrons 52 fainter 52 Higgs boson 52 meteorites 51 magnetosphere 51 sunspots 51 spectroscopic 51 Astrophysical Journal 51 moon Titan 50 hydrogen atoms 50 gamma ray 50 Astrophysical Journal Letters 50 spectra 50 photons 50 Cassini spacecraft 50 solar flares 50 Planck 50 Cassini 49 organic molecules 49 GRB 49 planet 49 Space Telescope 48 adaptive optics 48 auroras 48 telescopes 48 galactic 48 Very Large Telescope 48 spectroscopy 48 Hubble Telescope 48 astrobiology 47 luminosity 47 general relativity