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(Click for frequent words.) 66 Martian equator 66 Nili Fossae 66 Gusev crater 66 Vastitas Borealis 65 Meridiani Planum 64 Syrtis Major 62 thin crescent 62 Opportunity rover 62 Ares Vallis 62 Chryse Planitia 62 rover Opportunity 61 Bonneville Crater 61 NASA rovers Spirit 61 Comet #P/Churyumov-Gerasimenko 61 twin rover Spirit 61 Oceanus Procellarum 61 Mars Meridiani Planum 61 #P/Churyumov-Gerasimenko 61 Earth asteroid Itokawa 60 Shackleton Crater 60 gaseous planet 60 Endeavour Crater 60 lunar equator 60 lunar crust 60 twin rover Opportunity 60 Ontario Lacus 60 comet Churyumov Gerasimenko 59 Hellas Basin 59 Martian surface 59 Arabia Terra 59 slender crescent 59 Terra Meridiani 59 heavily cratered 59 Caloris Basin 59 Comet Churyumov Gerasimenko 59 Venusian surface 59 Terra Sirenum 59 HiRISE image 59 Samuel Oschin Telescope 58 polar vortex 58 Valles Marineris 58 Martian crater 58 Mars Odyssey spacecraft 58 rover Spirit 58 Candor Chasma 58 Planitia 58 Martian terrain 58 Martian polar 58 Elysium Planitia 58 rock outcrop 58 Hadley Rille 58 Rover Opportunity 58 asteroid Steins 58 Shackleton crater 58 Arkalyk Kazakhstan 58 six wheeled rover 58 Mars Gusev Crater 58 Cassini flyby 57 moon Phobos 57 planets Uranus 57 Taurus Littrow 57 Valles Marineris canyon 57 martian 57 Orientale Basin 57 asteroid Itokawa 57 martian soil 57 rover Spirit landed 57 comet #P/Churyumov-Gerasimenko 57 Saturnian moon Titan 57 Caloris 57 arctic plains 57 star Spica 57 Gusev Crater 56 Comet Hartley 56 Ringed Planet 56 Churyumov Gerasimenko 56 ecliptic plane 56 Deep Impact craft 56 waxing crescent 56 heliopause 56 comets asteroids 56 shadowy craters 56 lander 56 innermost planet 56 Comet Hartley 2 56 Ulysses spacecraft 56 Upsilon Andromedae b 56 constellation Eridanus 56 Saturnian system 56 stationary lander 56 smallest exoplanet 56 Oort Cloud 56 northern arctic plains 56 phyllosilicate 56 Martian arctic 56 magnetotail 56 Rosetta spacecraft 56 celestial sphere 56 Mars moon Phobos 56 Odyssey orbiter 56 vast Gusev Crater 55 NASA Spirit rover 55 Meridiani plains 55 bedrock outcropping 55 Itokawa 55 NASA Stardust spacecraft 55 moon Mimas 55 Martian plains 55 Titan flyby 55 Victoria Crater 55 Fra Mauro 55 Reiner Gamma 55 NASA rover Spirit 55 permanently shadowed crater 55 Sensing Satellite LCROSS 55 Ius Chasma 55 asteroid Eros 55 EPOXI spacecraft 55 subsurface ocean 55 Saturn Cassini 55 Endurance crater 55 Earth radii 55 Meridiani 55 magnetopause 55 ejecta blanket 55 Sojourner rover 55 Oort cloud 55 spacecraft thrusters 55 starlike object 55 LCROSS spacecraft 55 comets orbiting 55 penumbral shadow 55 waning crescent 55 zodiacal light 55 martian surface 55 Ranging spacecraft 55 Fomalhaut b 55 Kraken Mare 55 Red Planet 55 Kazakhstan steppe 55 layered bedrock 55 Orbiter LRO 55 MARSIS radar 55 reentry capsule 55 spiral galaxy NGC 54 Eta Aquarid meteor shower 54 moon permanently shadowed 54 ESA Mars 54 Orbiter MRO 54 CoRoT satellite 54 Hellas Planitia 54 Mars Odyssey orbiter 54 planet Gliese #g 54 RQ# 54 jovian 54 NASA Voyager spacecraft 54 quartz feldspar porphyry intrusive 54 Huygens lander 54 moonquakes 54 Clementine spacecraft 54 lander rover 54 constellation Aquarius 54 NASA Opportunity rover 54 Andaman Islands quake 54 cratered highlands 54 IBEX spacecraft 54 constellation Hercules 54 Olympus Mons 54 Opportunity Mars rover 54 Kuiper belt 54 rubbly 54 basaltic rocks 54 impactor spacecraft 54 constellation Andromeda 54 Nasa Deep Impact 54 Jupiter icy moons 54 Erebus Crater 54 midlatitudes 54 closest flyby 54 abyssal plain 54 comet nucleus 54 Martian landscape 54 umbral shadow 54 P Churyumov Gerasimenko 54 super perigee moon 54 Galileo spacecraft 54 moon Deimos 54 Cabeus crater 54 MUSES C 54 Saturn moon 54 constellation Virgo 54 aphelion 54 sunward 54 asteroid Vesta 54 GJ#b 54 telescopic observations 54 highly elliptical orbit 53 airglow 53 retrograde orbit 53 icy moons 53 Titan Saturn 53 frigid polar 53 polar plateau 53 galactic equator 53 Upsilon Andromedae 53 Mini SAR 53 equatorial latitudes 53 Mars Reconnaissance Orbiter 53 Jovian moons 53 Phoebe orbits 53 galaxy M# [002] 53 lunar highlands 53 lunar soil 53 irregularly shaped asteroid 53 Kepler 9c 53 interstellar boundary 53 exosphere 53 unmanned probes 53 Charon Pluto 53 smoothest flattest spot 53 Mars Pathfinder lander 53 Gamma Virginids 53 Jupiter Ganymede 53 Gliese #c 53 NASA rovers 53 waning gibbous 53 volcano Olympus Mons 53 Comet 9P/Tempel 1 53 lunar perigee 53 aboard Taurus XL 53 laser altimeter 53 Corot 7b 53 shadowed craters 53 Comet Boethin 53 QQ# 53 constellation Centaurus 53 Shiveluch 53 Endurance Crater 53 smoothest flattest 53 galactic disk 53 Asteroid Belt 53 Arkalyk 53 Capricornus 53 Saturn moon Enceladus 53 anticyclonic 53 lunar crater 53 orbiting Saturn 53 Mawrth Vallis 53 Comet Halley 53 spacecraft flyby 53 Chicxulub Crater 53 Manned missions 53 Virgo Cluster 53 volcanic moon Io 53 Huygens probe landed 53 Cabeus 53 moon Io 53 Antarctic Dry Valleys 53 Shuttle undocks 53 Express orbiter 53 bedrock outcrops 53 jagged ridge 53 Herschel Crater 53 Explorer WISE 53 Saturn moon Iapetus 52 NASA Lunar Crater 52 heliosheath 52 Atlantis undocks 52 waxing gibbous 52 Quadrantid meteor shower 52 Mini Thermal Emission 52 # Apophis 52 lunar module Eagle 52 geysers erupting 52 Quaoar 52 Kounotori2 52 cratons 52 Eridanus 52 ESA Huygens probe 52 mineral olivine 52 polar craters 52 Gamburtsev 52 Ranging MESSENGER spacecraft 52 planetary surfaces 52 Mars CRISM 52 planet magnetosphere 52 Brunt Ice Shelf 52 Nasa spacecraft 52 Curiosity rover 52 Comet Tempel 1 52 filamentary structures 52 Mössbauer spectrometer 52 Saturnian moons 52 comet Wild 52 Huygens spacecraft 52 Earth ionosphere 52 Comet Tempel Tuttle 52 ESA Rosetta 52 Pole Aitken 52 moon Enceladus 52 WD5 52 moonlet 52 Arsia Mons 52 lander Beagle 2 52 Nasa Mars Odyssey 52 Comet Encke 52 Crozet Islands 52 Saturn moon Mimas 52 P/# A2 52 Global Surveyor 52 NASA EPOXI mission 52 Kasei Valles 52 Gakkel Ridge 52 Nasa Mars Reconnaissance 52 Orionids 52 constellation Cygnus 52 ah dus 52 Martian orbit 52 lunar craters 52 lunar meteorites 52 waxing gibbous moon 52 prograde 52 moons orbiting Saturn 52 abyssal plains 52 retroreflector 52 Hematite Slope 52 HL Tau 52 andesitic rocks 52 sunlike star 52 constellation Sagittarius 52 moon Titan 52 comet McNaught 52 Jovian moon 52 MG J# +# 52 Voyager spacecraft 52 WISE telescope 52 Messenger spacecraft 52 permanently shadowed craters 52 Lava flows 52 comet Tempel Tuttle 52 magnetospheric 52 VD# [001] 52 permanently shadowed 52 moons Phobos 52 Bramley Murton 52 Mount Bosavi 52 Mars 52 Jurassic sandstone 52 albedo reflectivity 52 Mars rover Opportunity 52 Rover Spirit 51 Jupiter magnetosphere 51 TrES 4 51 polar layered 51 equatorial regions 51 active volcanism 51 Planck satellite 51 robotic lander 51 geomagnetic field 51 thin crescent moon 51 Comet Machholz 51 grabens 51 Earth asteroids NEAs 51 mesosphere 51 explosive volcanism 51 arcminutes 51 cometary debris 51 WISE spacecraft 51 Russia Kamchatka Peninsula 51 rover 51 Kazakhstan barren steppe 51 Cassini 51 GJ #b [001] 51 comet flyby 51 APXS 51 Huygens descent 51 Zeta Ophiuchi 51 equatorial 51 Mare Imbrium 51 Serpens Cauda 51 Lunar CRater Observation 51 perihelion 51 Weddell Sea 51 orbiting Mars 51 Philae lander 51 CoRoT 9b 51 constellation Carina 51 flyby spacecraft 51 Uranus Jupiter 51 moons orbiting 51 martian atmosphere 51 Ocean Salinity SMOS 51 stellar occultation 51 Saturnian moon 51 constellation Bootes 51 previously undrilled 51 circumstellar disk 51 Hayabusa spacecraft 51 Space Environment Geochemistry 51 THEMIS Images 51 Sermilik Fjord 51 ultramafic intrusives 51 constellation Leo 51 Palaeozoic sedimentary 51 NEAR Shoemaker 51 interferometric synthetic aperture radar 51 Comet Lulin 51 pericentre 51 twin Voyager spacecraft 51 gray hematite 51 Kuiper Belt Objects 51 Taurus Littrow Valley 51 protoplanet 51 fissure eruption 51 Hayabusa capsule 51 geosynchronous 51 Shepherding Spacecraft 51 Space ENvironment GEochemistry 51 GJ #b [002] 51 Mars Squyres 51 Kuiper belt objects 51 Squyres Cornell 51 crustal thickness 51 Stardust spacecraft 51 Mars Reconnaissance Orbiter MRO 51 Perseus constellation 51 Saturn Enceladus 51 Miniature Thermal Emission 51 Taurids 51 Lunar Reconnaissance Orbiter LRO 51 comet Hartley 2 51 permanently shadowed regions 51 interstellar particles 51 NASA rover Opportunity 51 Titan flybys 51 Moessbauer spectrometer 51 KAGUYA 51 tidal bulge 51 Viking orbiters 51 Aqua satellite 51 HD#b 51 McMurdo Dry Valleys 51 constellation Libra 51 hydrothermal fluid 51 exoplanets planets 51 comet chaser 51 cometary dust 50 Kanaga Volcano 50 Apophis asteroid 50 Epoxi 50 Comet NEAT 50 called gray hematite 50 martian rocks 50 deep convective clouds 50 Fossae 50 Cosmic Microwave Background 50 ExoMars rover 50 Kiruna Sweden 50 Noachian era 50 Mars Color Imager 50 DMSP F# 50 lunar orbiters 50 OMEGA instrument 50 Nihoa Island 50 SKY WATCH 50 Moderate Resolution Imaging 50 Shuttle Discovery blasts 50 granodiorite porphyry 50 lobate scarps 50 Pluto Charon 50 Venusian atmosphere 50 celestial equator 50 Rosetta orbiter 50 synchronous orbit 50 Beardmore Glacier 50 Fornax cluster 50 Elenin 50 nicknamed Bonneville 50 Mission SRTM 50 Enceladus flyby 50 THEMIS Image 50 orbital resonance 50 hole CJV 50 brecciated silicified 50 latite 50 Martian rover 50 Kazakhstan Baikonur Cosmodrome 50 NASA Cassini 50 robotic explorer 50 Stardust capsule 50 constellation Monoceros 50 Methone 50 orbital eccentricity 50 NASA LCROSS 50 COROT 7b 50 farside 50 Sinus Meridiani 50 meter diametre 50 geyser plumes 50 horst block 50 Pleiades star 50 Flyby spacecraft 50 Deep Impact flyby spacecraft 50 microscopic imager 50 Tharsis Rise 50 lowermost mantle 50 lunar orbiter Chang'e 50 spacecraft orbited 50 Yinghuo 1 50 waitress Ingrid Sufan 50 constellation Taurus 50 planet Uranus 50 Rosetta comet 50 copper impactor 50 orbits Saturn 50 smoggy atmosphere 50 star Fomalhaut 50 Mars Orbiter 50 MGS Mars Orbiter Camera 50 constellation Fornax 50 icy moon Enceladus 50 Sojourner Rover 50 Mercury flyby 50 Martian 50 Ross Ice Shelf 50 Tempel Tuttle 50 remote sensing instruments 50 angular boulders 50 Kepler Space Telescope 50 waning gibbous moon 50 GA6 50 Martian dust 50 gravitational keyhole 50 Geminid meteors 50 coronal hole 50 magma boiling 50 interstellar dust grains 50 Antarctic glacier 50 Composite Infrared Spectrometer 50 Today waxing Virgo 50 Discovery undocked 50 rotational axis 50 HiRISE images 50 lunar orbits 50 NASA Cassini spacecraft 50 Melas Chasma 50 Mars Orbiter Camera 50 Saturn outermost 50 Spirit Mars rover 50 Pu'u O'o 50 Cryosat 50 olivine rich 50 saprolitic 50 moons Europa 50 meteoroid 50 VY Canis Majoris 50 Depth SAFOD 50 Mars Opportunity rover 50 Orionid 50 equatorial plains 50 Cassini Huygens spacecraft 50 Cerro Pachon 50 Orion nebula 50 Axel Heiberg 50 geo synchronous 50 Deep Impact comet 50 Denisova Cave 50 Ruwenzori Mountains 50 lunar regolith 50 olivine mineral 50 Earth thermosphere 50 icy crust 50 Ring Nebula 50 shepherding spacecraft 50 erupting lava 50 elliptical orbits 50 Pancam 50 Tanegashima remote 50 Kamchatka peninsula 50 Quadrantid 50 Mpc 50 entered lunar orbit 49 cosmic ray particles 49 Lander robotic arm 49 moon Mab 49 Stardust mothership 49 westerly trough 49 COROT 49 Comet LINEAR 49 unmanned rover 49 tropopause 49 Caloris basin 49 ITCZ 49 Martian soil 49 Nunavut Territory coal 49 Gliese #d 49 whiz harmlessly 49 Eagle lunar lander 49 Hikurangi undersea trench 49 volcanic outcrops 49 WASP #b 49 Itokawa asteroid 49 Chile Atacama 49 Spirit rover 49 Titan smoggy 49 tectonically 49 PSR B# 49 hummocky 49 Earthlike planet 49 phyllosilicates 49 Gliese #e 49 gibbous 49 Phobos Grunt 49 Wilkinson Microwave Probe 49 Stardust spacecraft swooped 49 Cydonia region 49 yardangs 49 damaged thermal tiles 49 planets orbits 49 auroral activity 49 auroral oval 49 Pleiades cluster 49 spacecraft Chandrayaan 1 49 exo planet 49 arcsecond 49 regolith 49 Mars Odyssey Orbiter 49 Banerdt 49 Mars orbiting spacecraft 49 constellation Cetus 49 felsic tuff 49 Svalbard Islands 49 Muchachos Observatory 49 extrasolar 49 Geosynchronous orbit 49 Oriental Fault 49 exoplanetary 49 orbit GEO 49 tectonic activity 49 orbiting spacecraft 49 Borealis basin 49 Lake Untersee 49 Jovian atmosphere 49 Huygens Probe 49 Jupiter moon Io 49 hexagonal mirrors 49 scarps 49 vehicle PSLV C# 49 polar latitudes 49 Deep Impact eXtended Investigation 49 galaxy NGC 49 Toutatis 49 anorthosite 49 planetoid 49 Chasma Boreale 49 orbiting Kepler telescope 49 Orion constellation 49 volcanoclastic 49 ejecta plume 49 AU Mic 49 comet 49 Mars Odyssey 49 ESA ASI 49 substorm 49 Nares Strait 49 Main Shear Zone 49 basaltic lava 49 Lyrid meteor shower 49 elongated orbits 49 protoplanets 49 polar regions 49 GOCE 49 TrES 49 pyroclastics 49 cometary material 49 waxing crescent moon 49 crustal plate 49 Io volcanoes 49 pediment gravels 49 Solar TErrestrial RElations Observatory 49 circumstellar 49 volcanic plumes 49 interplanetary spacecraft 49 Earthlike 49 Jim Kauahikaua 49 silicified andesite 49 Deep Impact probe 49 elongated orbit 49 cluster NGC 49 Tharsis 49 shaded craters 49 New Horizons spacecraft 49 2 pronounced Vilt 49 Martian lander 49 Epsilon Eridani 49 Japan Hayabusa spacecraft 49 moonlike 49 arcseconds 49 MESSENGER spacecraft 49 Phoenix Mars Lander 49 outer corona 49 GEochemistry 49 silicate dust 49 sedimentary deposits 49 reconnaissance orbiter 49 Phoenix lander 49 circular orbit 49 Saturn rings 49 Svalbard archipelago 49 NASA Mars Odyssey 49 Martian rovers 49 ionized gas 49 palaeo channel 49 Amery Ice Shelf 49 Huygens 49 stratigraphically below 49 THEMIS satellites 49 spacecraft Cassini 49 Ultraviolet Imaging Spectrograph UVIS 49 constellation Ara 49 comet dust 49 magma ocean 49 Foton M3 49 Fermi telescope 49 silicified zone 49 MARSIS 49 Cygnus Lyra region 49 Mossbauer spectrometer 49 CoRoT #b 49 MESSENGER MErcury Surface 49 constellation Scorpius 49 Earth magnetosphere 49 sunspot cluster 49 Mars rovers Opportunity 49 MARSIS instrument 49 magnetosphere 49 Doppler measurements 49 Aram Chaos 49 tropical latitudes 49 gradiometer 49 Opportunity rovers 49 Laurasia 49 undersea volcanoes 48 Cape Adare 48 Steins asteroid 48 lunar poles 48 Kuiper Belt object 48 gabbro intrusive 48 earths surface 48 Cosmodrome 48 NASA twin rovers 48 Philae 48 Jupiter flyby 48 Convection Rotation 48 NASA MESSENGER spacecraft 48 NASA Kepler telescope 48 capsule parachuted 48 interstellar dust samples 48 lava flowed 48 mere fly bys 48 Khumbu Glacier 48 Io Europa 48 Plesetsk Cosmodrome 48 Chajnantor plateau 48 Corot 9b 48 Pozo Seco 48 gibbous moon 48 HD #b [001] 48 lunar surface 48 Tunguska meteorite 48 Gliese #G 48 planetary Transits 48 NASA Mars rover 48 Imaging Spectroradiometer MODIS instrument 48 Tunguska Siberia 48 Dumont d'Urville station 48 basalt rocks 48 magnetic geophysical anomaly 48 Jakobshavn 48 gray hematite mineral 48 lunar 48 Mazatzal 48 Saturn magnetosphere 48 Mars Lander 48 chalcedonic silica 48 axial tilt 48 orbited Jupiter 48 Ocean Salinity 48 Orcus Patera 48 Compact Reconnaissance Imaging Spectrometer 48 orbiter 48 apogee farthest point 48 Gerard Kuiper 48 hydrosphere 48 Mertz Glacier Tongue 48 claystone 48 Mount Karthala 48 lander robotic arm 48 Tanegashima Space Center 48 occulted 48 Guatemala sinkhole 48 planet Nibiru 48 Zarya module 48 S/# P2 48 CoRoT 7b 48 telescope Uranus 48 odometry 48 Undocking 48 Neutron Detector 48 Mössbauer 48 umbral 48 Earth objects NEOs 48 Viking Orbiter 48 Utopia Planitia 48 ringed planet 48 Cassini flybys 48 Jurassic sandstones 48 seafloors 48 Martian arctic plains 48 outer planets 48 Jupiter moons 48 X ray spectrometer 48 subhorizontal 48 Enceladus 48 satellites orbiting Earth 48 SIM PlanetQuest 48 cometary 48 constellations Cygnus 48 asteroidal 48 NASA Spacecraft 48 planet HD #b 48 crestal 48 STSS Demo 48 chromosphere 48 Nisqually Glacier 48 BLG #Lb 48 incandescent lava 48 Earth magnetotail 48 Phobos 48 liquid ethane 48 EPOCh 48 geothermal gradient 48 Nasa Jet Propulsion 48 plasmasphere 48 permanently shadowed lunar 48 Grímsvötn volcano 48 inner Oort Cloud 48 Cancri e 48 ESA Huygens 48 moon Ganymede 48 WNW trending 48 Kepler spacecraft 48 CALIPSO satellites 48 constellation Ursa Major 48 Mariana Arc 48 Saturn moons Titan 48 Puu Oo 48 weather satellite TIROS 48 asteroid 48 seafloor sediments 48 infrared spectral 48 upper troposphere 48 icecap 48 highly elliptical orbits 48 mu Arae 48 LCROSS mission 48 Tuamotu Archipelago 48 1m 3ft 48 orbiting 48 Helheim glacier 48 spinning clockwise 48 Eridani 48 meteoritic material 48 LAGEOS 48 Lutetia 48 heliospheric 48 Molten rock 48 tectonic uplift 48 Cassini Huygens 48 lunar orbiting spacecraft 48 Descent Imager Spectral Radiometer 48 planets asteroids 48 Qinghai Tibet plateau 48 Kuiper Belt objects 48 drogue parachute 48 eccentric orbits 48 Galilean satellites 48 THEMIS spacecraft 48 HIRES spectrometer 48 Cretaceous interval 48 pad #A 48 Polar Regions 48 Advanced Synthetic Aperture 48 alluvial gravels 48 icy comets 48 gabbro dykes 48 Iapetus 48 Kazakhstan Baikonur 48 meteoroids 48 equatorial orbit 48 constellation Auriga 48 hydroxyl molecules 48 ferric oxides 48 Denisova cave 48 situ measurements 48 Eta Aquarids 48 polygon shaped 48 Lake Cheko 48 cosmic microwave radiation 48 Envisat satellite 48 orbiter Cassini 48 Sensing Satellite 48 interstellar dust particles 48 semidesert 48 Ground penetrating radar 48 gabbros 48 subsurface 48 polar icecap 48 moon Dione 48 hematite mineral 48 occultations 48 Diviner instrument 48 windshield wiper maneuver 48 Cretaceous Jurassic 48 rovers Spirit 48 Planetary Fourier Spectrometer PFS 48 goethite 48 Astrological lore 48 Disko Island 48 colluvial 48 dolerite 48 mineralized peridotite 48 Mars Surveyor 48 Kermadec Arc 48 Swift Tuttle 48 spodumene bearing 48 Viking Lander 48 Jurassic formations 48 lensing galaxy 48 Induced Polarisation 48 Gerhard Schwehm 48 NASA CloudSat 48 InfiniTEM survey 48 heliosphere 48 ray Space Telescope 48 constellation Puppis 48 Halema'uma'u 48 Hesperian Epoch 48 Reconnaissance Orbiter 48 carbonaceous chondrite 48 magnetic polarity 48 Nankai Trough Zone 47 Kourou French Guiana 47 Huygens probe 47 Endeavour undocks 47 Hole EC# 47 Rongbuk 47 ESA SMART 47 kimberlitic bodies 47 Antarctic continent 47 Niobrara Shale formation 47 silicate rocks 47 Opportunity parachuted 47 ionised gas 47 equator 47 CoRoT 47 colder denser 47 Svalbard islands 47 GOCE satellite 47 ship Akademik Fyodorov 47 Mauna Kea Hawaii 47 ancient lakebed 47 ionized particles 47 Kepler #b 47 rover robotic arm 47 suborbital trajectory 47 axis perpendicular 47 ionized hydrogen 47 Jiuquan launch 47 hunting Kepler telescope 47 Amundsen Sea 47 Solar Dynamics Observatory 47 ejecta 47 Martian crust 47 Columbia Icefields 47 subglacial lakes 47 meteoroid impacts 47 waning crescent moon 47 Soil Moisture 47 basaltic 47 crossbedding 47 lunar orbiter Chandrayaan 47 ° #'N 47 talus slopes 47 warmer wetter 47 Whillans Ice Stream 47 faint smudge 47 Martian volcanoes 47 Iapetus Saturn