Related by context. Frequent words. (Click for all words.) 54 observatories 54 telescopes 51 amateur astronomers 50 astronomical objects 50 XMM Newton 49 observatory 49 Very Large Array 49 telescope 49 optical telescopes 49 Lowell Observatory 48 Kitt Peak 48 Palomar Observatory 48 NRAO 48 Telescopes 47 Arecibo Observatory 47 Telescope 47 Celestron 46 Observatories 46 Radio Astronomy Observatory 46 ESO 46 Gemini Observatory 46 LSST 45 WM Keck Observatory 45 astronomers 45 adaptive optics 44 optical telescope 44 ESO Very Large Telescope 43 star gazers 43 extrasolar planets 43 astronomy 43 NASA Kepler 43 astronomical observations 42 Observatory 42 IceCube 42 Thirty Meter Telescope 42 celestial objects 42 NASA Goddard 42 extrasolar planet 42 Very Large Telescope 41 hyperspectral 41 Space Telescope 41 astronomical observatory 41 Orion Nebula 41 infrared wavelengths 41 planetariums 41 exoplanets 41 Crab Nebula 41 Andromeda Galaxy 41 ASTER 41 Hinode 41 NASA JPL 41 Astronomy 41 distant galaxy 40 exoplanet 40 COROT 40 skywatchers 40 astronomer 40 infrared telescope 40 binocular 40 reconnaissance satellites 40 distant galaxies 40 HiRISE 40 Hubble Space Telescope 40 infrared 40 gravitational wave 40 orbiting telescope 40 JWST 40 robotic spacecraft 39 satellites 39 LRO 39 Hubble Telescope 39 Cassini Huygens 39 auroras 39 Hubble 39 NASA Cassini spacecraft 39 Andromeda galaxy 39 orbiting satellites 39 amateur astronomer 39 celestial bodies 38 celestial object 38 LiDAR 38 remote sensing satellites 38 Planetary Laboratory 38 NASA Chandra 38 astronomical 38 LCLS 38 spectroscopic 38 planetary science 38 Axsys 38 SDSS 38 Stargazers 38 Spitzer Space Telescope 38 WorldWide Telescope 38 constellation 38 habitable planets 38 lidar 38 Geminids 38 NASA Lunar Reconnaissance 38 GLAST 38 planetarium 38 SwRI