Related by context. Frequent words. (Click for all words.) 66 rocky planets 65 planets 63 planets orbiting 63 planet orbiting 61 exoplanets 61 extrasolar planets 60 exoplanet 58 brown dwarfs 57 habitable zone 57 Milky Way galaxy 56 infrared wavelengths 55 distant galaxies 54 distant galaxy 54 Solar System 53 planetary 53 galaxies 53 galaxy 53 heliosphere 53 quasars 53 brown dwarf 52 supernovae 52 celestial objects 52 astrophysical 52 orbits 52 planet 52 astronomers 51 dwarf galaxies 51 Gliese 51 Saturn rings 51 Milky Way 50 redshift 50 comets 50 asteroids 50 magnetosphere 50 Kuiper Belt 50 quasar 50 nebula 50 nebulae 49 gamma ray bursts 49 Enceladus 49 Uranus 49 asteroid belt 49 cosmic rays 49 gamma ray burst 49 pulsars 49 interstellar space 48 neutron star 48 galaxy clusters 48 comet 48 infrared radiation 48 supernovas 47 moons 47 gravitational waves 47 spiral galaxy 47 aurora 47 Astronomers 47 JWST 47 supermassive black holes 47 planetary scientist 47 Sedna 47 neutron stars 47 asteroid 47 cosmic microwave background 47 Spitzer Space Telescope 47 supernova 47 astronomer 47 cosmos 47 celestial bodies 47 universe 47 supermassive black hole 47 astrobiology 47 astrophysicists 46 organic molecules 46 Astrophysical Journal 46 neutrino 46 Betelgeuse 46 cosmologists 46 adaptive optics 46 orbiting 46 telescope 46 Kepler 46 moon Titan 45 Iapetus 45 auroras 45 sunspots 45 Earths 45 ionosphere 45 Lowell Observatory 45 telescopes 45 pulsar 45 meteor showers 45 Saturn moon 45 cosmic radiation 44 Earth orbit 44 Earth 44 constellations 44 galactic 44 Einstein theory 44 Astrophysical Journal Letters 44 THEMIS 44 Meridiani Planum