Related by context. Frequent words. (Click for all words.) 70 WM Keck Observatory 65 ESO Very Large Telescope 63 Very Large Telescope 61 microlensing 60 Gemini Observatory 60 optical telescope 60 XMM Newton 59 astronomers 59 optical telescopes 58 Lick Observatory 58 Spitzer Space Telescope 58 OGLE 57 telescopes 57 Mauna Kea 57 COROT 57 NASA Cassini spacecraft 56 infrared telescope 56 NASA Chandra 55 X ray emission 55 Cassini Huygens 55 extrasolar planets 55 telescope 55 Palomar Observatory 55 Telescope 55 NICMOS 55 HARPS 54 X ray Observatory 54 spectroscopic 54 distant galaxy 54 Hinode 54 Large Magellanic Cloud 53 Very Large Array 53 infrared spectrometer 53 extrasolar planet 53 infrared wavelengths 53 Arecibo Observatory 53 adaptive optics 53 Chandra X ray 53 exoplanet 53 MARSIS 53 interferometer 52 HD #b [002] 52 Cassini 52 planet orbiting 52 Kitt Peak 52 NASA Aqua 52 observatories 52 astronomical observations 52 planets orbiting 52 Spectrometer 52 THEMIS 52 astrophysicists 52 supernova remnant 51 CALIPSO 51 interferometry 51 exoplanets 51 volcanically active 51 Andromeda Galaxy 51 Orion Nebula 51 gamma ray burst 51 Milky Way Galaxy 51 Andromeda galaxy 51 gravitational lensing 51 moon Charon 51 GRBs 51 NASA Lunar Reconnaissance 51 Resolution Imaging 50 Space Telescope 50 polar caps 50 Saturn moon Enceladus 50 OSIRIS 50 Cassini spacecraft 50 Cancri 50 Eta Carinae 50 moon Titan 50 distant galaxies 50 unaided eye 50 MODIS 50 NASA Kepler 50 rocky planets 50 quasars 50 orbiting 50 globular cluster 50 brown dwarf 50 Fomalhaut 50 Voyager spacecraft 50 redshift 50 Astrophysics 50 Cassini orbiter 50 galaxy cluster 49 Monthly Notices 49 Thirty Meter Telescope 49 brown dwarfs 49 constellation Perseus 49 Astrophysical Journal 49 Mars Pathfinder 49 elliptical galaxies 49 astronomical objects 49 Global Surveyor 49 Titan Saturn 49 Mars Odyssey