Related by context. Frequent words. (Click for all words.) 68 telescope 64 optical telescope 62 optical telescopes 62 XMM Newton 61 orbiting telescope 60 telescopes 59 Cassini Huygens 59 Very Large Telescope 58 NASA Cassini spacecraft 58 extrasolar planet 58 spacecraft 57 spectrograph 57 ESO Very Large Telescope 57 WM Keck Observatory 57 Hubble Telescope 56 IceCube 56 Spitzer Space Telescope 56 Hubble Space Telescope 56 Hubble telescope 56 orbiting spacecraft 56 comet nucleus 55 Cassini spacecraft 55 gamma ray burst 55 asteroid 55 interferometer 55 panoramic camera 54 lunar orbiter 54 X ray Observatory 54 Space Telescope 54 Cassini orbiter 54 imager 54 Telescope 54 robotic spacecraft 54 NASA Chandra 54 spectrometer 54 Orion Nebula 54 GOCE 54 field Infrared Survey 53 orbiting 53 astronomers 53 astronomer 53 comet 53 Mars Reconnaissance Orbiter 53 moon Titan 53 remote sensing satellite 52 optical microscope 52 observatory 52 spectrometers 52 impactor 52 HD #b [002] 52 distant galaxy 52 synthetic aperture radar 52 Martian surface 52 spy satellites 52 Huygens probe 52 Saturn moon 52 extrasolar planets 52 THEMIS 52 HiRISE 52 spectroscopic 52 astronomical observations 52 Itokawa 52 rover Opportunity 52 comet dust 52 lunar surface 51 distant galaxies 51 observatories 51 satellites 51 scramjet 51 NASA Mars Reconnaissance 51 Cassini 51 Eta Carinae 51 transmission electron microscope 51 Huygens 51 infrared wavelengths 51 exoplanet 51 Deep Impact spacecraft 51 supernova explosion 51 orbiter 51 Lunar Reconnaissance Orbiter 51 LIGO 51 supernova remnant 51 Hubble 51 Deep Impact mission 51 remote sensing satellites 50 Kaguya 50 planet orbiting 50 NASA Mars Odyssey 50 Spectrometer 50 infrared camera 50 cosmic microwave background 50 infrared spectrometer 50 lander 50 satellites orbiting 50 rocky planets 50 Milky Way Galaxy 50 Martian soil 50 ringed planet 50 adaptive optics 50 CloudSat 50 JWST