Related by context. Frequent words. (Click for all words.) 79 supermassive black holes 77 neutron star 75 galaxies 74 quasar 71 Milky Way galaxy 70 quasars 70 galaxy 69 pulsar 68 galaxy clusters 67 neutron stars 66 Milky Way 66 supernovae 66 nebula 66 distant galaxies 66 gamma ray burst 65 supernova 64 brown dwarf 64 gamma rays 61 pulsars 60 gamma ray bursts 60 brown dwarfs 59 Enceladus 59 supernovas 59 comet 59 magnetic fields 59 planets 59 comets 58 exoplanets 58 magnetosphere 58 planets orbiting 58 exoplanet 57 neutrino 57 cosmic rays 57 atoms 56 GRB 56 extrasolar planets 56 particles 56 neutrons 56 neutrinos 55 nuclei 55 proton 55 subatomic particles 54 electrons 54 vortices 54 gravitational 53 orbits 53 Kuiper Belt 53 corona 53 astronomers 53 galactic 53 protons 52 fainter 52 gamma ray 52 solar flares 52 photons 52 electron 51 filaments 51 infrared wavelengths 51 Saturn rings 51 gaseous 51 magma 51 Solar System 51 interstellar space 51 asteroid belt 50 hydrogen atoms 50 suns 50 particle 50 asteroids 50 Sedna 50 outer layers 50 gravitational pull 50 orbiting 50 starlight 50 Spitzer Space Telescope 49 Galaxies 49 water vapor 49 astrophysicists 49 molten rock 49 comet Tempel 1 49 photon 49 asteroid 49 infrared radiation 48 auroras 48 Harvard Smithsonian 48 Astronomers 48 deuterium 47 luminosity 47 impactor 47 Gliese 46 general relativity 46 hydrothermal 46 Cassini spacecraft 46 sunspot 46 Saturn moon 46 Earth crust 46 spectra 46 Tempel 1 46 troposphere 46 dust particles 45 sunspots 45 molecule