Related by context. Frequent words. (Click for all words.) 56 Halley comet 55 Nicolaus Copernicus 54 Edwin Hubble 54 WASP #b 52 classical antiquity 52 papyri 52 Orion Nebula 52 XMM Newton 51 astronomers 51 Gliese #g 51 sundials 51 extrasolar planets 51 ancients 51 globular clusters 51 Ptolemy 51 planetary nebula 51 radial velocity 51 Crab Nebula 50 astronomical observations 50 HD #b [002] 50 Antikythera Mechanism 50 astronomer 49 magnetar 49 occultation 49 Ptolemaic 49 Rembrandt van Rijn 49 celestial bodies 49 Voyager spacecraft 49 medieval manuscripts 48 Halley Comet 48 planetary nebulae 48 Saturn rings 48 supernova explosion 48 planets 48 Algol 48 Johannes Kepler 48 supercontinent 48 magnetars 48 Galileo Galilei 48 Phaethon 48 extrasolar planet 48 celestial 47 Haumea 47 Egyptian pyramids 47 microlensing 47 astronomical objects 47 Clyde Tombaugh 47 GRB # 47 elliptical galaxies 47 planetoid 47 Milky Way Galaxy 47 dwarf galaxy 47 Rosetta stone 47 GRBs 47 OGLE 47 Otzi 46 Astrophysicist 46 colliding galaxies 46 Herodotus 46 Medieval Warm Period 46 Sumerians 46 photometry 46 Andromeda Galaxy 46 Greek philosophers 46 Andromeda galaxy 46 millenniums 46 Astronomer 46 supernovas 46 classical mythology 46 Niels Bohr 46 Cancri 46 feathered dinosaurs 46 Minoan 46 philologist 46 Eta Carinae 46 cosmologists 46 astronomical observatory 46 Burgess Shale 46 planets orbiting 46 nebulae 46 aurorae 46 distant galaxy 46 observable universe 46 Pentateuch 45 NASA Cassini 45 Cheops 45 astronomer Carl Sagan 45 solar nebula 45 Type Ia supernovae 45 Johann Wolfgang von Goethe 45 COROT 45 pulsars 45 planet orbits 45 supernova explosions 45 illuminated manuscripts 45 Babylonians 45 Lick Observatory 45 solstices 45 Corot 45 Inscriptions 45 WMAP