Related by context. Frequent words. (Click for all words.) 47 telescope 47 Hubble 47 XMM Newton 47 Hubble telescope 45 Space Telescope 44 Hubble Space Telescope 43 NASA Hubble Space 43 Spitzer Space Telescope 43 comet nucleus 42 HiRISE 42 WMAP 42 distant galaxy 42 NASA Cassini spacecraft 42 Hubble Telescope 41 extrasolar planet 41 Mars Reconnaissance Orbiter 41 orbiting spacecraft 41 eyepiece 40 Saturn rings 40 astronomers 40 astronomer 39 aperture 39 quasars 39 NASA 39 NASA Chandra 39 telescopes 39 adaptive optics 39 comet 39 optical telescopes 39 orbital debris 39 gamma ray burst 39 Saturn moons 39 dimmer 39 panoramic camera 38 infrared wavelengths 38 Lowell Observatory 38 JWST 38 spectrograph 38 distant galaxies 38 Nasa 38 supernovae 38 extrasolar planets 38 amateur astronomer 38 electron microscope 37 craters 37 Grunsfeld 37 galaxies 37 eye 37 optical telescope 37 planets orbiting 37 infrared 37 magnification 37 Cassini 37 sky 37 astrophysicists 37 Advanced Camera 37 galaxy cluster 37 observatory 37 skywatchers 36 Milky Way galaxy 36 scuff marks 36 IceCube 36 unaided eye 36 Very Large Telescope 36 quasar 36 Phoenix lander 36 interferometry 36 Cassini spacecraft 36 X ray Observatory 36 Andrew Feustel 36 imager 36 Kepler 36 ringed planet 36 Spacewalking astronauts 36 celestial objects 36 infrared detectors 36 microscopic 36 GLAST 36 WM Keck Observatory 36 pinholes 36 Chandra X ray 35 cloudy sky 35 MESSENGER 35 exoplanet 35 Perseids 35 scanning electron microscope 35 Astronomers 35 CCD camera 35 nebula 35 Mars rover 35 optical microscope 35 blurry 35 nebulae 35 specks 35 flyby 35 brighter 35 NASA Mars Reconnaissance 35 dimmest 35 pinhole 35 ultraviolet 35 gravitational lensing