Related by context. Frequent words. (Click for all words.) 68 rocky planets 67 habitable planet 64 super Earths 62 terrestrial planets 61 habitable planets 60 extrasolar planet 60 habitable zone 59 exoplanets 58 planets 58 Gliese #g 57 brown dwarfs 57 astrobiologists 57 exoplanet 57 planets orbiting 56 planet orbiting 56 extrasolar planets 56 hot Jupiters 56 Saturn moons 55 moon Europa 55 HD #b [002] 54 brown dwarf 52 quark gluon plasma 52 Meridiani 52 Saturn moon 52 equatorial regions 51 moon Titan 51 COROT 51 galaxy formation 51 silicates 51 Martian arctic 51 Titan Saturn 51 volcanically active 51 astronomical objects 51 Kuiper belt 51 Gliese 50 Cancri 50 NASA Kepler 50 Kuiper Belt 50 GRBs 50 extremophiles 50 Enceladus 50 UB# [003] 50 superfluidity 50 unaided eye 50 organic molecules 50 Earth asteroids 49 elliptical galaxies 49 globular clusters 49 geologically active 49 lunar poles 48 supersymmetry 48 Jupiter Saturn 48 Higgs Boson 48 WIMPs 48 Spitzer Space Telescope 48 outer planets 48 Solar System 48 globular cluster 48 comets 48 dwarf planets 48 moon Charon 48 Saturn moon Enceladus 47 distant galaxies 47 microlensing 47 meteorites 47 dwarf galaxies 47 galaxies 47 Orion Nebula 47 Astrophysical Journal 47 astronomers 47 Milky Way galaxy 47 spiral galaxies 47 neutron stars 47 distant galaxy 46 planet orbits 46 galaxy clusters 46 Earths 46 Milky Way Galaxy 46 high temperature superconductivity 46 Jupiter moons 46 Kepler telescope 46 asteroids 46 polar regions 46 polar caps 46 Jupiter Saturn Uranus 46 Meridiani Planum 46 comet Wild 46 Andromeda Galaxy 46 astrobiology 46 habitability 46 XMM Newton 46 planet 46 olivine 46 Cassini Huygens 46 martian 45 dwarf planet 45 supernovae 45 Mars 45 interstellar dust 45 Lutetia 45 cometary