Related by context. Frequent words. (Click for all words.) 62 distant galaxies 62 celestial bodies 61 nebulae 59 constellations 59 planets 59 quasars 59 planets orbiting 58 extrasolar planets 58 astronomers 57 XMM Newton 57 exoplanets 57 astrophysical 56 brown dwarfs 56 supernovae 56 globular clusters 55 telescopes 55 supernovas 55 galaxies 54 distant galaxy 54 pulsars 54 astronomy 54 quasar 54 auroras 54 gamma ray bursts 53 infrared wavelengths 53 Perseids 53 galaxy clusters 52 planet orbiting 52 celestial 52 solar flares 52 amateur astronomers 52 exoplanet 52 redshift 51 ringed planet 51 galaxy 51 astrophysicists 51 gamma ray burst 51 Milky Way galaxy 51 rocky planets 51 meteor showers 51 meteors 51 Pleiades 51 Cassini 51 observatories 50 Milky Way 50 nebula 50 Astronomers 50 cosmic ray 50 cosmos 50 aurora 50 gravitational waves 50 telescope 50 moon Titan 50 asteroids 50 Astronomy 50 orbits 50 moons 49 comets 49 Spitzer Space Telescope 49 cosmic rays 49 NASA Cassini spacecraft 49 starlight 49 Solar System 49 neutron stars 49 Telescopes 49 meteor shower 48 Saturn rings 48 brown dwarf 48 cosmic microwave background 48 cosmological 48 THEMIS 48 Enceladus 48 spiral galaxy 48 Chandra X ray 47 WMAP 47 CMEs 47 interstellar dust 47 spectroscopic 47 wavelengths 47 stargazers 47 subatomic particles 47 gamma rays 47 interstellar medium 47 MESSENGER 47 neutron star 47 comet 47 spectra 47 HiRISE 46 supermassive black holes 46 Cassini spacecraft 46 dwarf galaxies 46 orbiting 46 magnetosphere 46 adaptive optics 46 Very Large Telescope 46 cosmologists 46 Lunar Reconnaissance Orbiter 45 Kuiper Belt 45 Betelgeuse 45 supernova 45 Hubble Space Telescope