Related by context. Frequent words. (Click for all words.) 84 telescopes 73 Telescope 72 observatory 66 Hubble 65 Hubble Space Telescope 64 observatories 63 astronomers 62 Hubble telescope 61 adaptive optics 60 spectrograph 59 astronomy 59 spectrometer 59 spacecraft 58 astronomer 56 satellites 56 planetarium 56 Spitzer Space Telescope 56 orbiting 55 amateur astronomers 54 Cassini 54 Astronomy 54 amateur astronomer 53 comet 53 quasars 53 Mars Reconnaissance Orbiter 53 infrared 53 gamma ray burst 52 extrasolar planets 52 Observatory 52 infrared wavelengths 52 distant galaxies 52 Astronomers 51 Huygens 51 orbiter 51 infrared camera 51 exoplanet 50 Webb Space Telescope 50 spectrometers 50 Saturn rings 50 impactor 50 celestial objects 50 gamma ray bursts 50 satellite 49 Cassini spacecraft 49 imager 49 Solar System 49 Mars rover 49 MESSENGER 49 Herschel 49 seismometers 49 LRO 49 planets orbiting 49 lander 49 GPS satellites 49 electron microscope 49 rover 48 quasar 48 flyby 48 solar arrays 48 asteroid 48 binoculars 48 planetary scientist 48 spy satellites 48 Space Telescope Science 48 SETI 48 solar flares 48 Astrophysics 48 LCROSS 47 STEREO 47 galaxies 47 NASA Jet Propulsion Laboratory 47 Mars rovers 47 Huygens probe 47 astrophysicists 47 meteor shower 47 telescopic 47 Orbiter 47 Kepler 47 robotic arm 47 supernova 47 orbiters 47 Planck 47 starlight 47 binocular 47 synchrotron 47 Nasa 47 Astronomer 46 aurora 46 Mauna Kea 46 NASA 46 microscopes 46 asteroids 46 moon 46 particle accelerator 46 Milky Way galaxy 46 Space Agency 46 constellation 46 Applied Physics Laboratory 46 pulsars 46 pulsar 46 astrophysicist