Related by context. Frequent words. (Click for all words.) 60 Valles Marineris 57 heavily cratered 56 polar vortex 55 basaltic 54 lithosphere 53 undersea volcanoes 53 Olympus Mons 53 Chicxulub 53 Earth magnetosphere 52 crustal 52 heliosphere 52 cryosphere 51 scarps 51 Tharsis 51 accretion disk 51 volcanically active 51 meteoroid 51 ejecta 51 Saturn rings 51 magnetosphere 50 graben 50 hydrothermal breccia 50 hydrothermally altered 50 meteorite impacts 50 Kuiper belt 49 lava flowing 49 Petermann Glacier 49 Oort Cloud 49 icy crust 49 volcanic 49 moonlets 49 volcanism 49 spacetime 49 protoplanetary disk 49 Earth crust 49 Opportunity rover 48 lava tubes 48 magnetic reconnection 48 Earthlike 48 corrugations 48 landforms 48 Galileo spacecraft 48 Haumea 48 galaxy NGC 48 Meteor Crater 48 continental crust 48 extensional 48 Mimas 48 supercontinent 48 heliosheath 48 ringed planet 48 colliding galaxies 48 landmasses 48 Saturn moons 48 Martian landscape 48 magmatic 48 comet nucleus 48 pyroclastic 48 igneous rock 48 mud volcanoes 48 solar corona 47 depositional 47 auroral 47 torus 47 X ray emission 47 calcareous 47 basalts 47 Iapetus 47 basalt 47 WASP #b 47 mesosphere 47 Andromeda galaxy 47 rock outcrop 47 striations 47 craters 47 Kilauea Volcano 46 Namib Desert 46 lithological 46 Carina Nebula 46 icecap 46 outer crust 46 ridges 46 quartz stockwork 46 Wilkins Ice Shelf 46 volcanic plume 46 crust 46 magnetar 46 Tibetan Plateau 46 solar nebula 46 hardened lava 46 meteoroids 46 supervolcano 46 caldera 46 planetary nebulae 46 tectonic fault 46 geologically active 46 tectonic 45 twin rover Spirit 45 planet Uranus 45 clasts 45 igneous