Related by context. Frequent words. (Click for all words.) 69 optical telescopes 68 telescopes 65 observatories 63 infrared telescope 63 telescope 61 optical telescope 61 satellites orbiting 61 COROT 61 XMM Newton 60 CALIPSO 59 Very Large Telescope 59 interplanetary spacecraft 59 astronomical observations 59 THEMIS 59 Cassini Huygens 58 Titan Saturn 58 NASA ESA Hubble 58 moon Charon 58 satellites 58 orbiting spacecraft 58 ESO Very Large Telescope 58 astronomical objects 58 X ray telescope 58 interferometer 58 radiometer 57 spectrometers 57 astronomers 57 NASA Cassini spacecraft 57 planetary missions 57 spectroscopic 57 JWST 57 Voyager spacecraft 57 robotic spacecraft 56 geostationary satellites 56 MARSIS 56 remote sensing satellites 56 spacecraft 56 orbiting Mars 56 NASA Lunar Reconnaissance 56 orbiting telescope 56 Global Surveyor 56 infrared wavelengths 56 WM Keck Observatory 56 HRSC 56 interferometry 56 infrared detectors 56 Spectrometer 56 Mars Reconnaissance Orbiter 56 comet nucleus 56 Space Telescope 55 celestial objects 55 orbiting observatory 55 IceCube 55 infrared spectrometer 55 optical microscopy 55 celestial object 55 extrasolar planets 55 gravitational wave 55 NASA Mars Reconnaissance 55 Spitzer Space Telescope 55 spacecrafts 55 synthetic aperture radar 54 Andromeda Galaxy 54 Cassini orbiter 54 GOCE 54 optical microscope 54 visible wavelengths 54 observatory 54 New Horizons spacecraft 54 CCD camera 54 Arecibo Observatory 54 multispectral 54 hyperspectral 54 Cassini 54 orbiting satellites 54 Telescopes 54 Mars orbiter 54 Hinode 54 planets orbiting 53 CloudSat 53 GRBs 53 Saturn moons 53 ICESat 53 lunar poles 53 GLAST 53 HD #b [002] 53 Saturn moon Enceladus 53 adaptive optics 53 Very Large Array 53 HiRISE 53 Thirty Meter Telescope 53 rocky planets 53 wavelengths 53 seismographs 53 Hubble Space Telescope 53 distant galaxy 53 NASA Kepler 53 asteroids 53 ionospheric 53 extrasolar planet 53 X ray emission