Related by context. Frequent words. (Click for all words.) 50 surface 46 subsurface 46 iron oxides 45 bathymetry 43 surficial 42 clasts 40 regolith 38 quartz stockwork 38 calcrete 37 Martian surface 37 surfaces 37 surface roughness 37 igneous rock 36 glacial till 36 chemically inert 36 nanosized 36 pebbly 36 icy crust 36 macroscale 36 silicates 36 Martian landscape 35 electrically conducting 35 martian soil 35 Martian rocks 34 microstructures 34 Martian soil 33 overlying 33 lunar soil 33 beneath 33 salt crystals 33 nonporous 33 conductivity 33 martian surface 32 silica 32 seafloor 32 textured surfaces 32 temperature gradient 32 Martian arctic 31 sediments 31 ejecta 30 Lake Vostok 30 alluvium 30 spalling 30 seabed 30 silty 30 gravels 29 ridges 29 coating 29 solder joints 29 layers 29 microscale 29 coarse sand 29 silicon substrate 29 oceanic crust 29 Santa Anita synthetic 29 thin layer 29 scratches 29 Surface 28 interfacial 28 outer shell 28 granules 28 decomposed granite 28 earth crust 27 crushed limestone 27 twin rover Spirit 27 sandy 27 lithosphere 26 lakebed 26 spongy 25 protective coating 25 polar vortex 25 rubberized 25 compacted soil 25 underneath 24 substrate 24 uneven surfaces 24 hardpan 23 crustal 23 roadbeds 23 cooling fins 23 oblique angle 23 layer 23 macadam 23 rubberized surface 23 rubberised 23 crust 23 sand 23 curved surfaces 22 sediment 21 absorbs moisture 21 damp sponge 21 roadbed 20 magma chamber 19 dirt 19 subfloor 18 sidewalls 18 surfacing 17 edges 17 asphalt 16 blacktop 15 soil