Related by context. Frequent words. (Click for all words.) 77 telescopes 67 observatory 64 telescope 62 astronomers 60 amateur astronomers 59 satellites 56 Telescope 56 astronomy 56 Telescopes 56 seismographs 54 seismometers 53 Very Large Telescope 53 Astronomy 53 Observatory 53 Lowell Observatory 52 orbiting satellites 52 Spitzer Space Telescope 52 XMM Newton 51 astronomer 51 Astrophysics 51 celestial objects 50 remote sensing 50 Envisat 49 X ray Observatory 49 HiRISE 49 adaptive optics 49 meteor showers 48 astrophysicists 48 auroras 48 Astronomers 48 planetariums 48 geophysicists 48 asteroids 48 interferometer 48 THEMIS 47 planetarium 47 Hubble Space Telescope 47 gamma ray bursts 47 Space Telescope 47 lidar 47 seismology 47 NASA Chandra 46 astrophysical 46 planets orbiting 46 cosmic ray 46 distant galaxies 46 unmanned spacecraft 46 physicists 46 satellite 46 spacecraft 46 meteor shower 46 Mauna Kea 45 GPS satellites 45 distant galaxy 45 orbiting 45 extrasolar planets 45 solar flares 45 lunar missions 45 Mars Reconnaissance Orbiter 45 Radio Astronomy Observatory 45 celestial bodies 45 Earth Observation 45 radars 45 infrared wavelengths 45 planetary scientist 45 quasars 44 detectors 44 stargazers 44 Landsat 44 spectrometers 44 orbiters 44 volcanoes 44 comets 44 gamma ray burst 44 polar regions 44 NASA Goddard 44 Saturn rings 44 Geophysical Institute 44 Perseids 44 remote sensing satellite 43 spectroscopic 43 meteors 43 Space Agency 43 spacecrafts 43 Mars Odyssey 43 galaxy clusters 43 Cassini 43 Earth Observatory 43 seismologists 43 Applied Physics Laboratory 43 LRO 43 Hubble Telescope 43 particle accelerators 43 ionosphere 43 scientists 43 galaxies 43 LCROSS 43 planets 43 meteorites 43 oceanographers 43 flybys