Related by context. Frequent words. (Click for all words.) 55 Nicolaus Copernicus 54 Johannes Kepler 52 Galileo Galilei 51 SIRTF 50 Edwin Hubble 49 Niels Bohr 49 Brahe 49 astronomer 47 Paul Dirac 47 philologist 47 astronomical observations 46 Saturn rings 46 planet Uranus 46 cosmologists 46 Niels Bohr Institute 46 astronomer Carl Sagan 46 microlensing 46 theoretical physicists 46 interplanetary spacecraft 46 Johann Wolfgang von Goethe 46 WASP #b 46 extrasolar planets 45 Szilard 45 Cosmologists 45 Wernher von Braun 45 asteroid Ceres 45 Paracelsus 45 Richard Feynman 45 Edward Teller 45 Blaise Pascal 45 Einstein theory 45 moon Charon 45 Phaethon 45 astronomers 44 physicist Albert Einstein 44 physicists 44 celestial bodies 44 Astrophysicists 44 general relativity 44 Clyde Tombaugh 44 orbiting telescope 44 God Particle 44 Werner Heisenberg 44 COROT 43 theoreticians 43 Gravity Probe B 43 innermost planet 43 outer planets 43 Leibniz 43 climate modelers 43 Galaxy Evolution 43 radial velocity 43 Heisenberg 43 orbiting planets 43 dwarf planets 43 Schopenhauer 43 geoid 43 HD #b [002] 43 physicist 43 Kepler 42 Lowell Observatory 42 Halley comet 42 sundials 42 astronomical observatory 42 composer Leonard Bernstein 42 astronomy 42 elliptical galaxies 42 Hayden Planetarium 42 Astronomer 42 Galileo spacecraft 42 Leonids 42 mathematician 42 Sigmund Freud 42 Nibiru 42 Filippenko 42 gravitational lensing 42 Kaiser Wilhelm 42 University Lamont Doherty 42 Lunar Prospector 42 skywatchers 42 NASA Cassini 42 Lutetia 42 theoretical physicist 42 planet orbiting 42 Einstein 42 Lick Observatory 42 occultation 42 Nasa Jet Propulsion 41 philosophers 41 Martin Heidegger 41 SELENE 41 aurora borealis 41 Eta Carinae 41 Cancri 41 galaxy formation 41 Higgs particle 41 quantum theory 41 hot Jupiters 41 Scorpius 41 Cassini Huygens 41 Jupiter moons