Related by context. Frequent words. (Click for all words.) 55 rocky planets 55 Lunine 55 protoplanetary disks 55 terrestrial planets 54 galaxy formation 53 Carl Pilcher 53 WASP #b 52 habitable planets 52 interstellar clouds 52 stellar nurseries 51 Carnegie Observatories 51 Filippenko 51 solar corona 51 Earthlike 51 William Borucki 51 SIRTF 51 nanobacteria 51 potentially habitable 51 planetary nebulae 50 protoplanetary disk 50 Jet Propulsion Laboratory JPL 50 lunar craters 50 Oort Cloud 50 habitable zones 49 planetary geologist 49 icy moons 49 habitable planet 49 Kuiper belt 49 planetary scientist 49 planetary science 49 supernova explosions 49 supernova remnants 49 Lick Observatory 49 NASA Astrobiology Institute 49 planets orbiting 49 interstellar medium 48 Exoplanet 48 Felisa Wolfe Simon 48 magnetars 48 astrophysical 48 photosphere 48 Planetary Physics 48 Carolyn Porco 48 supernovas 48 elliptical galaxies 48 astrobiologists 48 NASA Kepler 48 undersea volcanoes 48 galaxy clusters 48 exosphere 48 Nasa Jet Propulsion 47 extraterrestrial civilizations 47 protostar 47 IBM Almaden Research 47 Jet Propulsion Lab 47 globular clusters 47 astrobiology 47 nanosystems 47 extrasolar planets 47 colliding galaxies 47 meteorite impacts 47 moon Europa 47 quasars 47 nebulas 47 Andromeda galaxy 47 Supernovae 47 Seth Shostak 47 Eagle Nebula 47 particle detectors 47 Poinar 47 Solar System 47 extrasolar planet 47 ionized gas 47 exoplanets 47 gaseous planets 47 supernova explosion 46 Galaxy Evolution 46 metallicity 46 planet orbiting 46 CfA 46 Astrophysicists 46 super Earths 46 magnetar 46 high temperature superconductivity 46 Planetary Science Institute 46 solar nebula 46 Type Ia supernovae 46 planets 46 underwater volcanoes 46 Udry 46 ultracold 46 Cassini radar 46 colliders 46 planetary 46 protostars 46 photochemistry 46 hydrothermal vent 46 Michael A'Hearn 46 active galactic nuclei 46 JPL manages 46 nebulae