Related by context. Frequent words. (Click for all words.) 55 Phaethon 53 Edwin Hubble 53 Halley comet 50 astronomer Carl Sagan 49 Halley Comet 49 Astrophysicist 49 Richard Feynman 49 Paul Dirac 48 Astronomer Royal 47 Professor Stephen Hawking 47 WASP #b 47 planet Uranus 47 Niels Bohr 47 Isaac Newton 47 discoverer 47 Carl Sagan 47 supermoon 46 Clyde Tombaugh 46 Einstein 46 distant galaxy 46 Galileo Galilei 46 HD #b [002] 45 Buckminster Fuller 45 Corot 45 Johannes Kepler 45 Comet Tempel 1 45 Nicolaus Copernicus 45 OGLE 45 Comet McNaught 45 Leonardo DaVinci 45 HAT P 45 classical antiquity 44 GRB # 44 Crab Nebula 44 Thomas Malthus 44 Andromeda galaxy 44 Epicurus 44 planetoid 44 innermost planet 44 Francis Crick 44 Lutetia 44 James Lovelock 44 constellation Leo 44 Venusian 44 Cancri 44 Amerigo Vespucci 43 Algol 43 Galileo spacecraft 43 Scorpius 43 HG Wells 43 Sedna 43 Herschel 43 COROT 43 boson 43 astronomer 43 Werner Heisenberg 42 Neil deGrasse Tyson 42 perihelion 42 Frank Borman 42 Geminids 42 SIRTF 42 Mandelbrot 42 WG Grace 42 Roman mythology 42 philologist 42 Pythagoras 42 Albert Einstein 42 Gregor Mendel 42 Robert Peary 42 cosmonaut Yuri Gagarin 42 Cetus 42 composer Leonard Bernstein 42 Fomalhaut 42 comet 42 God Particle 42 E = mc 42 constellation Perseus 42 Andromeda Galaxy 41 RQ# 41 Mathematician 41 celestial phenomenon 41 Orion Nebula 41 Selfish Gene 41 Feynman 41 Galaxy Evolution 41 Leonids 41 Aleister Crowley 41 Oort Cloud 41 Astronomer 41 Isambard Kingdom Brunel 41 physicist Albert Einstein 41 Samuel Pepys 41 occultation 41 Muybridge 41 ecliptic 41 Roman goddess 41 Eadweard Muybridge 41 radial velocity 41 Eta Carinae 41 NASA Cassini 41 Paracelsus