Planets Solar system paper Contents 1 Jupiter 1 1.1 Structure ............................................... 1 1.1.1 Composition ......................................... 1 1.1.2 Mass and size ......................................... 2 1.1.3 Internal structure ....................................... 2 1.2 Atmosphere .............................................. 3 1.2.1 Cloud layers ......................................... 3 1.2.2 Great Red Spot and other vortices .............................. 4 1.3 Planetary rings ............................................ 4 1.4 Magnetosphere ............................................ 5 1.5 Orbit and rotation ........................................... 5 1.6 Observation .............................................. 6 1.7 Research and exploration ....................................... 6 1.7.1 Pre-telescopic research .................................... 6 1.7.2 Ground-based telescope research ............................... 7 1.7.3 Radiotelescope research ................................... 8 1.7.4 Exploration with space probes ................................ 8 1.8 Moons ................................................. 9 1.8.1 Galilean moons ........................................ 10 1.8.2 Classification of moons .................................... 10 1.9 Interaction with the Solar System ................................... 10 1.9.1 Impacts ............................................ 11 1.10 Possibility of life ........................................... 12 1.11 Mythology .............................................. 12 1.12 See also ................................................ 12 1.13 Notes ................................................. 13 1.14 References .............................................. 13 1.15 Further reading ............................................ 18 1.16 External links ............................................. 18 2 Mars 19 2.1 Physical characteristics ........................................ 19 2.1.1 Internal structure ....................................... 20 i ii CONTENTS 2.1.2 Surface geology ....................................... 20 2.1.3 Soil .............................................. 21 2.1.4 Hydrology .......................................... 21 2.1.5 Geography and naming of surface features .......................... 23 2.1.6 Atmosphere ......................................... 26 2.1.7 Climate ............................................ 28 2.2 Orbit and rotation ........................................... 28 2.3 Search for life ............................................. 29 2.4 Habitability .............................................. 30 2.5 Exploration missions ......................................... 30 2.6 Astronomy on Mars .......................................... 30 2.7 Viewing ................................................ 31 2.7.1 Closest approaches ...................................... 32 2.8 Historical observations ........................................ 32 2.8.1 Ancient and medieval observations .............................. 33 2.8.2 Martian “canals” ...................................... 33 2.8.3 Spacecraft visitation ..................................... 34 2.9 In culture ............................................... 34 2.9.1 Intelligent “Martians” ................................... 34 2.10 Moons ................................................. 36 2.11 Gallery ................................................ 37 2.12 See also ................................................ 37 2.13 Notes ................................................. 37 2.14 References .............................................. 37 2.15 External links ............................................. 45 3 Mercury 47 3.1 Common meanings .......................................... 47 3.2 Places ................................................. 47 3.3 In the military ............................................. 47 3.4 Transportation ............................................. 47 3.5 In entertainment ............................................ 47 3.5.1 Music ............................................. 47 3.5.2 Comics ............................................ 48 3.5.3 Other ............................................. 48 3.6 Technology .............................................. 48 3.6.1 Computing .......................................... 48 3.7 Sports ................................................. 48 3.8 Publications .............................................. 48 3.9 Radio stations ............................................. 48 3.10 In business ............................................... 48 3.11 Other uses ............................................... 48 CONTENTS iii 3.12 See also ................................................ 49 4 Neptune 50 4.1 History ................................................. 50 4.1.1 Discovery ........................................... 50 4.1.2 Naming ............................................ 51 4.1.3 Status ............................................. 52 4.2 Composition and structure ....................................... 52 4.2.1 Internal structure ....................................... 52 4.2.2 Atmosphere .......................................... 52 4.2.3 Magnetosphere ........................................ 53 4.3 Planetary rings ............................................. 54 4.4 Climate ................................................ 54 4.4.1 Storms ............................................ 55 4.4.2 Internal heating ........................................ 55 4.5 Orbit and rotation ........................................... 56 4.5.1 Orbital resonances ...................................... 56 4.6 Formation and migration ....................................... 57 4.7 Moons ................................................. 57 4.8 Observation .............................................. 58 4.9 Exploration .............................................. 58 4.10 See also ................................................ 59 4.11 Notes ................................................. 59 4.12 References ............................................... 59 4.13 Bibliography .............................................. 64 4.14 Further reading ............................................ 64 4.15 External links ............................................. 64 5 Saturn 65 5.1 Physical characteristics ........................................ 65 5.1.1 Internal structure ....................................... 65 5.2 Atmosphere .............................................. 66 5.2.1 Cloud layers .......................................... 66 5.2.2 North pole hexagonal cloud pattern .............................. 67 5.2.3 South pole vortex ....................................... 67 5.2.4 Other features ......................................... 68 5.3 Magnetosphere ............................................ 68 5.4 Orbit and rotation ........................................... 68 5.5 Planetary rings ............................................. 69 5.6 Natural satellites ............................................ 69 5.7 History of exploration ......................................... 70 5.7.1 Ancient observations ..................................... 70 iv CONTENTS 5.7.2 European observations (17th–19th centuries) ......................... 70 5.7.3 Modern NASA and ESA probes ............................... 71 5.8 Observation .............................................. 72 5.9 In culture ............................................... 73 5.10 See also ................................................ 74 5.11 Notes ................................................. 74 5.12 References ............................................... 74 5.13 Further reading ............................................ 78 5.14 External links ............................................. 79 6 Uranus 80 6.1 History ................................................ 80 6.1.1 Discovery ........................................... 80 6.1.2 Naming ............................................ 81 6.1.3 Name ............................................. 82 6.2 Orbit and rotation ........................................... 82 6.2.1 Axial tilt ........................................... 83 6.2.2 Visibility ........................................... 83 6.3 Internal structure ........................................... 83 6.3.1 Internal heat ......................................... 84 6.4 Atmosphere .............................................. 84 6.4.1 Composition ......................................... 84 6.4.2 Troposphere ......................................... 85 6.4.3 Upper atmosphere ...................................... 85 6.5 Planetary rings ............................................ 86 6.6 Magnetosphere ............................................ 86 6.7 Climate ................................................ 87 6.7.1 Banded structure, winds and clouds ............................. 87 6.7.2 Seasonal variation ...................................... 88 6.8 Formation ............................................... 89 6.9 Moons ................................................. 89 6.10 Exploration .............................................. 90 6.11 In culture ............................................... 90 6.12 See also ................................................ 91 6.13 Notes ................................................. 91 6.14 References .............................................