Related by context. Frequent words. (Click for all words.) 76 exoplanets 76 planets 75 planet orbiting 75 extrasolar planets 74 rocky planets 70 exoplanet 68 brown dwarfs 67 brown dwarf 65 Milky Way galaxy 63 supernovae 63 dwarf galaxies 63 quasars 62 astronomers 62 Spitzer Space Telescope 62 quasar 62 galaxies 62 distant galaxies 61 Gliese 61 neutron star 61 galaxy 61 orbits 60 Astronomers 60 habitable zone 59 supernovas 59 asteroids 59 celestial objects 59 infrared wavelengths 59 pulsars 59 gamma ray burst 59 Milky Way 58 comets 58 supermassive black hole 58 nebulae 58 neutron stars 58 supernova 58 galaxy clusters 58 celestial bodies 57 Solar System 57 comet 57 Sedna 57 nebula 56 pulsar 56 supermassive black holes 56 Kuiper Belt 56 gamma ray bursts 56 asteroid 56 orbiting 55 Earths 55 fainter 55 planetary 55 redshift 55 moons 54 astrophysicists 54 Enceladus 54 Saturn rings 54 NASA Chandra 54 telescopes 52 Very Large Telescope 52 Cassini spacecraft 52 Saturn moon 51 spectra 51 Mars 51 sunspot 51 asteroid belt 51 sunspots 51 Martian surface 51 meteorites 51 organic molecules 51 spectrometers 51 neutrinos 51 WMAP 50 gravitational waves 50 Red Planet 50 Kepler 50 STEREO 50 Uranus 50 solar flares 50 cosmic microwave background 50 neutrino 49 UB# [003] 49 Space Telescope 49 adaptive optics 49 moon Titan 49 spectroscopic 49 hydrothermal vents 49 telescope 49 Mars Global Surveyor 49 Cassini 49 quark 49 Meridiani Planum 49 planet 48 gamma rays 48 Mars Reconnaissance Orbiter 48 Tempel 1 48 magnetosphere 48 galactic 48 Phobos 48 suns 48 corona 48 Chandra X ray 48 Galaxies