Related by context. Frequent words. (Click for all words.) 78 exoplanets 75 extrasolar planets 71 brown dwarf 71 brown dwarfs 70 planets orbiting 67 planets 64 Sedna 63 quasars 63 gamma ray burst 63 pulsars 63 supernova 62 astronomers 62 quasar 62 Milky Way galaxy 62 redshift 62 gamma ray bursts 62 galaxies 61 supernovae 61 galaxy 61 distant galaxies 60 pulsar 60 neutron star 60 Spitzer Space Telescope 60 habitable zone 59 galaxy clusters 59 neutrino 59 asteroid 59 neutron stars 58 Enceladus 58 Gliese 58 comet 58 supermassive black hole 57 Kuiper Belt 57 comets 57 Milky Way 57 infrared wavelengths 56 supernovas 56 Astronomers 56 nebula 56 Kepler 56 gravitational waves 55 spectroscopic 55 Solar System 54 dwarf planet 54 GRB 54 Saturn moon 54 planetary 54 asteroids 54 astrophysicists 54 meteorites 53 astronomer 53 sunspot 53 Pluto 52 orbits 52 supermassive black holes 52 Saturn rings 52 neutrinos 52 infrared radiation 52 Astrophysical Journal 52 telescopes 52 celestial objects 51 Cassini spacecraft 51 fainter 51 Planck 51 Higgs boson 51 Cassini 51 adaptive optics 51 spectra 51 telescope 50 spectroscopy 50 cosmic rays 50 asteroid belt 50 planet 50 magnetosphere 50 gamma rays 50 orbiting 50 gamma ray 49 sunspots 49 solar flares 49 galactic 49 moons 49 Hubble Space Telescope 49 celestial bodies 49 Earths 49 Martian surface 49 Uranus 48 Mars Reconnaissance Orbiter 48 infrared 48 photon 48 organic molecules 48 polar regions 48 Astrophysics 48 starlight 48 Hubble 48 quark 48 troposphere 47 photons 47 subatomic particles 47 atoms 47 general relativity 47 astronomy