Related by context. Frequent words. (Click for all words.) 71 infrared telescope 64 Cassini Huygens 63 X ray telescope 63 XMM Newton 61 COROT 61 NASA Cassini spacecraft 61 Cassini spacecraft 60 NASA Kepler 60 telescope 59 optical telescope 59 Kepler telescope 58 orbiting telescope 58 NASA ESA Hubble 58 Spitzer Space Telescope 57 extrasolar planet 56 celestial object 56 Cassini orbiter 56 orbiting spacecraft 56 orbiting observatory 56 THEMIS 56 Orbiting Carbon Observatory 56 NASA Lunar Reconnaissance 56 New Horizons spacecraft 56 Opportunity rover 55 microlensing 55 spacecraft 55 Mars orbiter 55 gamma ray burst 55 IceCube 55 adaptive optics 55 Ariane rocket 55 JWST 55 robotic spacecraft 55 NASA Chandra 55 optical telescopes 55 CALIPSO 55 X ray Observatory 55 WM Keck Observatory 54 moon Charon 54 telescopes 54 astronomical observatory 54 CloudSat 54 Saturn moon Enceladus 54 Lunar Reconnaissance Orbiter 54 Gravity Probe B 54 spectrograph 54 Saturn moon 54 EPOXI 54 astronomers 54 Space Telescope 54 CubeSat 54 ESO Very Large Telescope 53 astronomical observations 53 planetary missions 53 synthetic aperture radar 53 GLAST 53 field Infrared Survey 53 Very Large Telescope 53 SELENE 53 Saturn rings 53 extrasolar planets 53 interferometer 53 Stardust spacecraft 53 Very Large Array 53 Spectrometer 53 GOCE 52 Cassini 52 astronomer 52 MESSENGER 52 lunar orbiter 52 Ares IX rocket 52 OSIRIS 52 PASADENA Calif. NASA 52 HD #b [002] 52 Mars Pathfinder 52 Titan Saturn 52 NASA Mars Reconnaissance 52 ringed planet 52 Deep Impact mission 52 NASA Goddard 52 exoplanet 52 spaceplane 52 Oceansat 2 52 MARSIS 51 asteroid 51 moon Titan 51 infrared spectrometer 51 Hubble Space Telescope 51 OGLE 51 NASA Aqua 51 scramjet 51 Webb Space Telescope 51 hypersonic flight 51 rover Opportunity 51 gravitational wave 51 comet nucleus 51 solar arrays 51 Jet Propulsion Laboratory JPL 51 LCROSS 51 interferometry 51 WMAP