Related by context. Frequent words. (Click for all words.) 60 crust 59 lithosphere 58 regolith 56 ice crystals 54 moon Europa 54 martian surface 54 silicates 54 sedimentary rock 54 crevasses 53 glacial till 53 calcite 53 polar caps 53 Martian surface 52 ejecta 52 Saturn moon 52 spherical shape 52 thin layer 51 silty 51 craters 51 rocky planets 51 ionized gas 51 Enceladus 51 Saturn moon Enceladus 51 meteoroids 51 cirrus clouds 50 icecap 50 olivine 50 Saturn rings 50 subsurface 50 surface 50 comet nucleus 50 Iapetus 50 moon Titan 50 landforms 50 lava flows 50 volcanic rock 50 crystal lattice 50 iron oxides 50 refreezing 50 Weddell Sea 50 pebbly 50 outer layers 50 basalt 49 Saturn moons 49 basalts 49 rock formations 49 gullies 49 martian 49 supercooled 49 permafrost 49 outer layer 49 magnetosphere 49 aerosol particles 49 crystals 49 Meridiani Planum 49 equatorial regions 49 Martian atmosphere 49 talus 49 sediments 49 ridges 49 stalagmites 49 earth crust 48 graphene sheets 48 spacetime 48 thick layer 48 outermost layer 48 crevices 48 interstellar dust 48 insulating layer 48 meltwater 48 molten rock 48 Earth magnetosphere 48 gas hydrates 48 mudstone 48 volcanic plume 48 convective 48 nuclei 48 crusts 48 Martian arctic 48 meteoroid 48 carbonaceous 47 polar regions 47 heliosphere 47 lava 47 Martian landscape 47 rock outcrop 47 water vapor 47 geologically active 47 interstellar medium 47 crater 47 vortices 47 torus 47 sulphates 47 methane hydrates 47 cumulus clouds 47 hot Jupiters 47 Earth crust 46 landmasses 46 crystalline structure 46 lakebed 46 mid latitudes