Related by context. Frequent words. (Click for all words.) 66 observatory 58 infrared telescope 57 optical telescope 55 telescopes 55 telescope 55 Keck Observatory 55 Pan STARRS 54 observatories 52 microlensing 51 archeologists 51 WM Keck Observatory 51 Thirty Meter Telescope 51 medieval fortress 50 IceCube 50 particle detector 50 interplanetary spacecraft 50 Lick Observatory 50 archeological 49 geodetic 49 optical telescopes 49 planetarium 49 astronomers 49 archaeological 49 astronomy 49 Palomar Observatory 49 astronomer 48 archaeologists 48 archaeological finds 48 landform 48 extrasolar planet 48 extinct volcano 48 Observatories 48 Observatory 47 sundial 47 Kitt Peak 47 Astronomy 47 Egyptian pyramids 47 particle physics laboratory 46 meteorite 46 moon Charon 46 limestone cave 46 ESO Very Large Telescope 46 orbiting telescope 46 astronomical observations 46 Lowell Observatory 46 archeological dig 46 rock outcrop 46 dinosaur fossil 46 stargazer 45 cupola 45 lava tubes 45 stupa 45 archaeological excavation 45 COROT 45 icecap 45 Very Large Array 45 powerful particle accelerator 44 Mauna Kea 44 Griffith Observatory 44 sundials 44 Galileo Galilei 44 Very Large Telescope 44 occultation 44 archaeologist 44 Telescope 44 X ray telescope 44 botanical garden 44 meteor shower 44 SELENE 44 stupas 44 Stupa 44 Titan Saturn 44 Cassini Huygens 44 OGLE 44 dinosaur fossils 44 seismology 44 amateur astronomers 44 volcanically active 44 Gliese #g 43 dinosaur skeleton 43 stalagmite 43 Lutetia 43 orbiting Saturn 43 archaeological dig 43 excavation 43 innermost planet 43 archeologist 43 archaeological excavations 43 Gothic cathedral 43 remote sensing satellite 43 moon Titan 43 Arecibo Observatory 43 Herodium 43 promontory 43 distant galaxy 43 Archeological 43 lava tube 43 volcanic crater 42 adaptive optics 42 petroglyph 42 Galaxy Evolution