Related by context. Frequent words. (Click for all words.) 60 IntergalaticEarth 60 planet 57 asteroids comets 57 inhospitable environments 57 potentially habitable 57 habitable worlds 56 Earthlike 56 subsurface ocean 55 extrasolar 55 Nasdaq SPWRA SPWRB designs 55 Kepler #b 54 Caltech manages 54 Polar AAWW operates 54 By Laurie Kulikowski 54 seismically active regions 54 habitable planet 53 priests shuffled 53 BY VINCENT MAO 53 Exoplanets 53 planetary embryos 52 Exoplanet 52 driest inhabited continent 52 spacecraft orbiting 52 planets orbiting stars 52 Earthlike planets 52 driest continent 52 permafrost thaws 52 Goldilocks planet 52 observing satellites 52 biocapacity 52 earths 51 icy moons 51 meteor impacts 51 permafrost melts 51 permanently shadowed craters 51 By Sarah Trotto 51 GJ #b [001] 51 Solar flares 51 tidally locked 51 supervolcanoes 51 By BEVERLY CORBELL 51 EDN III 51 nourish starved bodies 51 Gliese #g 51 unmanned probes 51 By DANIE HARRELSON 51 Virgo Cluster 51 volcanically active 51 interplanetary spacecraft 51 gravitational microlensing 51 By TheStreet Wire 51 outer crust 51 cleanest greenest 51 penguins seals 50 By HARVEY SIMPSON 50 launched Operation Scorched 50 polar oceans 50 cryosphere 50 By Riva Froymovich 50 extraterrestrial civilizations 50 gaseous planets 50 warming gases 50 exosphere 50 plutoids 50 volcanic vents 50 unseeable 50 planets astronomers 50 interstellar boundary 50 gaseous planet 50 experience hath shewn 50 e chigliak 50 moon Europa 50 JPL manages 50 Mount Tambora buried 50 primitive organisms 50 sulfate aerosols 49 Venusian atmosphere 49 ozone layer depletion 49 NASA Spacecraft 49 By NATHAN BRUTTELL 49 By ALLEN GEMAEHLICH 49 By RICK KRETZSCHMAR 49 Gliese #d 49 gigaton 49 biosignatures 49 By PopEater Staff 49 Owen Gingerich 49 heavily cratered 49 By Candia Dames 49 Asteroid Belt 49 Titan Saturn 49 By DENNIS WEBB 49 Carbon dioxide CO2 49 AP IMPACT Predator 49 Goldilocks zone 49 terra preta 49 biogeochemical cycles 49 Beta Pictoris 49 Neutron stars 48 Meteor showers 48 Extinctions