Contents VI/4 Astronomy, Astrophysics, and Cosmology B: Solar System 4 The Solar System.............................................................................................................  1 

4.1 The Sun 	1 
4.1.1 The quiet Sun...................................................................................................................  1 

4.1.1.1 Solar global parameters (MICHAEL STIX) ......................................................................... 1 

4.1.1.2 Solar interior (MICHAEL STIX) ......................................................................................... 3 

4.1.1.2.1 Standard model ................................................................................................................  3 

4.1.1.2.2 Solar neutrinos.................................................................................................................  3 

4.1.1.2.3 Global oscillations ...........................................................................................................  5 

4.1.1.2.4 	Convection zone ..............................................................................................................  6 

4.1.1.2.5 	Solar rotation and meridional circulation......................................................................... 6 

4.1.1.2.6 	General magnetic field .....................................................................................................  7 
References for 4.1.1.1 and 4.1.1.2 ................................................................................... 8 

4.1.1.3 	The solar energy spectrum (KLAUS WILHELM) ................................................................ 10 

4.1.1.3.1 	Solar irradiance and spectral irradiance ........................................................................... 11 

4.1.1.3.2 	Solar radiance and spectral radiance ................................................................................ 15 

4.1.1.3.3 	The second solar spectrum...............................................................................................  17 

4.1.1.3.4 	References for 4.1.1.3 ......................................................................................................  18 

4.1.1.4 	Solar photosphere and chromosphere (MATTHIAS STEFFEN) ........................................... 21 

4.1.1.4.1 	Mean vertical temperature structure ................................................................................ 21 

4.1.1.4.2 	3D structure and dynamics of the solar photosphere and chromosphere ......................... 39 

4.1.1.4.3 	References for 4.1.1.4 ......................................................................................................  58 

4.1.1.5 	Solar transition region and quiet corona (KLAUS WILHELM) ........................................... 65 

4.1.1.5.1 	The transition region........................................................................................................  65 

4.1.1.5.2 	The quiet corona ..............................................................................................................  69 

4.1.1.5.3 	References for 4.1.1.5 ......................................................................................................  74 

4.1.1.6 	Radio emission of the quiet Sun (ARNOLD BENZ) ........................................................... 80 

4.1.1.6.1 	Flux density of the quiet sun full disk radio emission...................................................... 80 

4.1.1.6.2 	Brightness distribution across the quiet solar disk........................................................... 82 

4.1.1.6.3 	Slowly varying radio emission of the sun ........................................................................ 84 

4.1.1.6.4 	References for 4.1.1.6 ......................................................................................................  88 

4.1.2 	Solar activity....................................................................................................................  90 

4.1.2.1 	Active regions (KLAUS WILHELM) ................................................................................... 90 

4.1.2.1.1 	References for 4.1.2.1 ......................................................................................................  94 

4.1.2.2 	11-year solar cycle (SAMI SOLANKI, NATALIE KRIVOVA) ................................................ 97 

4.1.2.2.1 	The sunspot cycle ............................................................................................................  97 

4.1.2.2.2 	The magnetic cycle ..........................................................................................................  100 

4.1.2.2.3 	Irradiance and other parameters.......................................................................................  101 

Contents 
4.1.2.2.4 Longer term variations and secular change...................................................................... 104 

4.1.2.2.5 References for 4.1.2.2 ......................................................................................................  106 

4.1.2.3 Sunspots (SAMI SOLANKI, NATALIE KRIVOVA) ................................................................ 109 

4.1.2.3.1 General characteristics.....................................................................................................  109 

4.1.2.3.2 Intensity and temperature structure ..................................................................................  110 

4.1.2.3.3 Magnetic field structure ...................................................................................................  112 

4.1.2.3.4 Flows and oscillations......................................................................................................  114 

4.1.2.3.5 Sunspot fine structure ......................................................................................................  114 

4.1.2.3.6 References for 4.1.2.3 ......................................................................................................  115 

4.1.2.4 Faculae and plage (SAMI SOLANKI, NATALIE KRIVOVA) .................................................. 119 

4.1.2.4.1 General characteristics.....................................................................................................  119 

4.1.2.4.2 Location and size .............................................................................................................  119 

4.1.2.4.3 Intensity and temperature structure ..................................................................................  120 

4.1.2.4.4 B-field structure ...............................................................................................................  123 

4.1.2.4.5 Velocity structure .............................................................................................................  125 

4.1.2.4.6 References for 4.1.2.4 ......................................................................................................  125 

4.1.2.5 Prominences and ejecta (KLAUS WILHELM) ..................................................................... 127 

4.1.2.5.1 Prominences.....................................................................................................................  127 

4.1.2.5.2 Filaments .........................................................................................................................  127 

4.1.2.5.3 Eruptive prominences, filaments, and coronal mass ejections ......................................... 128 

4.1.2.5.4 Spicules and macrospicules .............................................................................................  129 

4.1.2.5.5 Jets and tornadoes............................................................................................................  131 

4.1.2.5.6 References for 4.1.2.5 ......................................................................................................  132 

4.1.2.6 Coronal active regions (KLAUS WILHELM) ...................................................................... 135 

4.1.2.6.1 Coronal oscillations and waves ........................................................................................  135 

4.1.2.6.2 References for 4.1.2.6 ......................................................................................................  137 

4.1.2.7 Flares (KLAUS WILHELM) ................................................................................................ 139 

4.1.2.7.1 Flare signatures................................................................................................................  139 

4.1.2.7.2 White-light flares.............................................................................................................  142 

4.1.2.7.3 Flare physics ....................................................................................................................  142 

4.1.2.7.4 References for 4.1.2.7 ......................................................................................................  143 

4.1.2.8 Radio bursts of the non-thermal Sun (ARNOLD BENZ) ..................................................... 148 

4.1.2.8.1 Solar radio bursts.............................................................................................................  148 

4.1.2.8.2 References for 4.1.2.8 ......................................................................................................  159 

4.2 The planets and their satellites ......................................................................................... 160 

4.2.1 Introduction (TILMAN SPOHN) ......................................................................................... 160 

4.2.1.1 Structure and dimension of the Solar System .................................................................. 161 

4.2.1.2 Definition of a planet in the Solar System ....................................................................... 162 

4.2.1.3 References for 4.2.1 .........................................................................................................  162 

4.2.2 Basic data of planetary bodies (HAUKE HUSSMANN, FRANK SOHL, JRGEN OBERST) .... 163 
4.2.2.1 General definitions...........................................................................................................  163 

4.2.2.1.1 Orbital elements...............................................................................................................  163 

4.2.2.1.2 Time standards.................................................................................................................  164 

4.2.2.1.3 Astronomical units...........................................................................................................  165 

4.2.2.2 Planets..............................................................................................................................  166 

4.2.2.3 Dwarf planets...................................................................................................................  167 

4.2.2.4 Satellites ..........................................................................................................................  167 

4.2.2.5 	Rings................................................................................................................................  169 

4.2.2.6 	References for 4.2.2 .........................................................................................................  181 

4.2.3 	Terrestrial planets and satellites .......................................................................................  182 

4.2.3.1 	Geodetic and geophysical data (MATTHIAS GROTT, HAUKE HUSSMANN, JRGEN 182 OBERST, MARITA WHLISCH) .......................................................................................... 
4.2.3.1.1 	Introduction .....................................................................................................................  182 

4.2.3.1.2 	Rotation and shape ...........................................................................................................  183 

4.2.3.1.3 	Gravity studies.................................................................................................................  192 

4.2.3.1.4 	Topography ......................................................................................................................  196 

4.2.3.1.5 	References for 4.2.3.1 ......................................................................................................  199 

4.2.3.2 	Planetary interiors (FRANK SOHL,FRANK W.WAGNER,HAUKE HUSSMANN,MATTHIAS GROTT) ................. 200 
4.2.3.2.1 	Introduction .....................................................................................................................  200 

4.2.3.2.2 	Basic equations and models.............................................................................................  202 

4.2.3.2.3 	Typical structure models..................................................................................................  210 

4.2.3.2.4 	References for 4.2.3.2 ......................................................................................................  221 

4.2.3.3 	Planetary seismology (MARTIN KNAPMEYER) ................................................................. 225 

4.2.3.3.1 	Introduction .....................................................................................................................  225 

4.2.3.3.2 	Mercury ...........................................................................................................................  226 

4.2.3.3.3 	Venus...............................................................................................................................  228 

4.2.3.3.4 	Earth ................................................................................................................................  229 

4.2.3.3.5 	Moon ...............................................................................................................................  230 

4.2.3.3.6 	Mars .................................................................................................................................  245 

4.2.3.3.7 	References for 4.2.3.3 ......................................................................................................  251 

4.2.3.4 	Dynamics and thermal evolution (DORIS BREUER) .......................................................... 254 

4.2.3.4.1 	Introduction .....................................................................................................................  254 

4.2.3.4.2 	Thermal and chemical convection ................................................................................... 255 

4.2.3.4.3 	Field equations and parameterization .............................................................................. 256 

4.2.3.4.4 	Material parameters: viscosity and radioactive heat sources ........................................... 260 

4.2.3.4.5 	Dynamics and thermal evolution of terrestrial planets..................................................... 261 

4.2.3.4.6 	References for 4.2.3.4 ......................................................................................................  267 

4.2.3.5 	Planetary geology (ERNST HAUBER, ROLAND WAGNER) ................................................. 271 

4.2.3.5.1 	Craters and chronology....................................................................................................  271 

4.2.3.5.2 	Volcanism........................................................................................................................  281 

4.2.3.5.3 	Tectonics..........................................................................................................................  308 

4.2.3.5.4 	Erosion, transport and sedimentation............................................................................... 323 

4.2.3.5.5 	Nomenclature (JUDIT JNCHEN AND MARITA WHLISCH) ............................................... 332 

4.2.3.5.6 	References for 4.2.3.5 ......................................................................................................  337 

4.2.3.6 	Planetary photometry and spectroscopy (KATRIN STEPHAN) ........................................... 353 

4.2.3.6.1 	Photometric properties of planetary surfaces................................................................... 353 

4.2.3.6.2 	Spectral properties of planetary surfaces ......................................................................... 360 

4.2.3.6.3 	References for 4.2.3.6 ......................................................................................................  374 

XII Contents 
4.2.3.7 Atmospheres of the planets and satellites (JOHN LEE GRENFELL) .................................... 378 

4.2.3.6.1 Exospheres of small planets and satellites .......................................................................  378 

4.2.3.6.2 Venus...............................................................................................................................  378 

4.2.3.6.3 Mars .................................................................................................................................  380 

4.2.3.6.4 Galilean satellites .............................................................................................................  381 

4.2.3.6.5 Titan.................................................................................................................................  382 

4.2.3.6.6 Pluto, Charon and Triton .................................................................................................  383 

4.2.3.6.7 References for 4.2.3.7 ......................................................................................................  383 

4.2.3.8 Magnetic fields (TILMAN SPOHN) .................................................................................... 386 

4.2.3.8.1 Dynamos..........................................................................................................................  386 

4.2.3.8.2 Magnetic fields of the terrestrial planets and satellites .................................................... 388 

4.2.3.8.3 References for 4.2.3.8 ......................................................................................................  391 

4.2.4 Planets of the outer Solar System (TILMAN SPOHN, JOHN LEE GRENFELL) ...................... 392 

4.2.4.1 Rotation, radii, shapes, gravity fields............................................................................... 392 

4.2.4.2 Giant planet atmospheres.................................................................................................  393 

4.2.4.3 Interior models.................................................................................................................  397 

4.2.4.4 Luminosity and thermal evolution ................................................................................... 399 

4.2.4.5 Magnetic fields ................................................................................................................  399 

4.2.4.6 References for 4.2.4 .........................................................................................................  402 

4.2.5 Exoplanets (JOHN LEE GRENFELL) ................................................................................... 404 

4.2.5.1 General properties............................................................................................................  404 

4.2.5.2 Observation methods .......................................................................................................  404 

4.2.5.3 Types of exoplanets .........................................................................................................  405 

4.2.5.4 Terms used in exoplanet research.................................................................................... 406 

4.2.5.5 Missions...........................................................................................................................  406 

4.2.5.6 References for 4.2.5 .........................................................................................................  406 

4.2.6 Missions (JUDIT JNCHEN) .............................................................................................. 408 

4.2.6.1 The inner Solar System....................................................................................................  409 

4.2.6.2 The outer Solar System....................................................................................................  412 

4.2.6.3 Missions to other celestial bodies .................................................................................... 413 

4.2.6.4 References for 4.2.6 .........................................................................................................  419 

4.3 Small bodies in the Solar System..................................................................................... 421 

4.3.1 The asteroids (ALAN W. HARRIS) .................................................................................... 421 

4.3.1.1 Asteroid discoveries.........................................................................................................  421 

4.3.1.2 Dynamical groupings.......................................................................................................  421 

4.3.1.3 Asteroid taxonomy...........................................................................................................  421 

4.3.1.4 Near-Earth asteroids and potentially hazardous asteroids................................................ 422 

4.3.1.5 Asteroid families ..............................................................................................................  425 

4.3.1.6 Asteroids with satellites and asteroid densities ................................................................ 425 

4.3.1.7 Asteroids with comet-like characteristics ........................................................................ 428 

4.3.1.8 Dwarf planets...................................................................................................................  429 

4.3.1.9 Rendezvous and fly-by missions to asteroids................................................................... 430 

4.3.1.10 Asteroid naming conventions/numbering ........................................................................ 430 

4.3.1.11 References for 4.3.1 .........................................................................................................  431 

4.3.2 Meteors (INGRID MANN) .................................................................................................. 434 

4.3.2.1 Introduction .....................................................................................................................  434 

4.3.2.1.1 Meteor phenomenology ...................................................................................................  434 

4.3.2.1.2 Definitions .......................................................................................................................  435 

4.3.2.2 Observations ....................................................................................................................  436 

4.3.2.2.1 Optical observations ........................................................................................................  436 

4.3.2.2.2 Radio observations ..........................................................................................................  438 

4.3.2.2.3 Data archives and information for observers ................................................................... 439 

4.3.2.3 Meteor fluxes, sources and orbits .................................................................................... 440 

4.3.2.3.1 Meteor fluxes and sources ...............................................................................................  440 

4.3.2.3.2 Meteoroid flux onto Earth ...............................................................................................  440 

4.3.2.3.3 Meteor showers and their orbits.......................................................................................  441 

4.3.2.3.4 Sporadic meteors and their orbits ....................................................................................  442 

4.3.2.3.4 Sporadic meteors and their orbits ....................................................................................  443 

4.3.2.4 Composition and properties .............................................................................................  444 

4.3.2.4.1 Fireballs and falls.............................................................................................................  444 

4.3.2.4.2 Meteoroid properties derived from meteor characteristics .............................................. 444 

4.3.2.4.3 Meteoroid compositions derived from meteor spectroscopy ........................................... 445 

4.3.2.5 References for 4.3.2 .........................................................................................................  447 

4.3.3 Meteorites (PETER HOPPE) ............................................................................................... 450 

4.3.3.1 Definition and nomenclature ............................................................................................  450 

4.3.3.2 Significance of meteorite study........................................................................................  450 

4.3.3.3 Classification ...................................................................................................................  450 

4.3.3.4 Chemical composition of chondrites ................................................................................ 452 

4.3.3.5 Isotopic compositions ......................................................................................................  455 

4.3.3.6 Organic matter .................................................................................................................  457 

4.3.3.7 Presolar grains .................................................................................................................  457 

4.3.3.8 Origin of meteorites.........................................................................................................  460 

4.3.3.9 References for 4.3.3 .........................................................................................................  461 

4.3.4 Comets (RITA SCHULZ, GIAN-PAOLO TOZZI) ................................................................... 467 

4.3.4.1 Mechanical data ...............................................................................................................  467 

4.3.4.2 Photometry and polarimetry ............................................................................................ 477 

4.3.4.3 Multi-wavelength spectroscopic observations ................................................................. 480 

4.3.4.4 Measurements from space missions................................................................................. 485 

4.3.4.5 Nucleus ............................................................................................................................  485 

4.3.4.6 Coma................................................................................................................................  491 

4.3.4.7 Tails.................................................................................................................................  492 

4.3.4.8 The nature of cometary dust ............................................................................................  494 

4.3.4.9 Laboratory studies relevant to comets ............................................................................. 496 

4.3.4.10 References for 4.3.4 .........................................................................................................  497 

4.3.5 Interplanetary dust (EBERHARD GRN, VALERI DIKAREV) .............................................. 501 

4.3.5.1 Introduction .....................................................................................................................  501 

4.3.5.2 Measurement techniques..................................................................................................  502 

4.3.5.2.1 In-situ measurements .......................................................................................................  502 

4.3.5.2.2 Micro crater studies .........................................................................................................  504 

4.3.5.2.3 Dust sample return...........................................................................................................  506 

4.3.5.2.4 Atmospheric collection....................................................................................................  506 

4.3.5.2.5 Meteor radars...................................................................................................................  506 

4.3.5.2.6 Remote sensing of the Zodiacal cloud ............................................................................. 507 

4.3.5.3 Observations ....................................................................................................................  508 

4.3.5.3.1 Zodiacal light...................................................................................................................  508 

4.3.5.3.2 Thermal emission.............................................................................................................  509 

XIV 	Contents 
4.3.5.3.3 Size distribution at 1 AU .................................................................................................  510 

4.3.5.3.4 Chemical and physical properties .................................................................................... 511 

4.3.5.3.4.1 In-situ measurements .......................................................................................................  511 

4.3.5.3.4.2 Analysis of collected dust particles..................................................................................  514 

4.3.5.3.5 Flux measurements in the interplanetary dust cloud ........................................................ 518 

4.3.5.3.6 Solar System dust streams................................................................................................  519 

4.3.5.3.7 Interstellar dust in the heliosphere ...................................................................................  520 

4.3.5.4 Theory..............................................................................................................................  522 

4.3.5.4.1 Sources ............................................................................................................................  522 

4.3.5.4.2 Dynamics .........................................................................................................................  522 

4.3.5.4.3 Sinks ................................................................................................................................  524 

4.3.5.4.4 Populations ......................................................................................................................  524 

4.3.5.5 References for 4.3.5 .........................................................................................................  527 

4.3.6 Interplanetary particles and magnetic fields (BERNDT KLECKER) .................................... 537 

4.3.6.1 Interplanetary plasma and magnetic field (solar wind) .................................................... 537 

4.3.6.2 Energetic particles in interplanetary space ....................................................................... 541 

4.3.6.2.1 Solar energetic particle composition and charge states .................................................... 541 

4.3.6.2.2 Solar energetic particle injection and coronal propagation.............................................. 544 

4.3.6.2.3 Interplanetary propagation of solar cosmic rays .............................................................. 545 

4.3.6.2.4 Corotating energetic particle events.................................................................................  547 

4.3.6.2.5 Modulation of galactic cosmic rays ................................................................................. 548 

4.3.6.2.6 Anomalous component of low energy cosmic rays.......................................................... 551 

4.3.6.3 Gases of non-solar origin in the Solar System ................................................................. 554 

4.3.6.3.1 	Introduction .....................................................................................................................  554 

4.3.6.3.2 	Determination of the interstellar gas distribution in the heliosphere ................................ 555 

4.4 	Abundances of the elements in the Solar System (KATHARINA LODDERS, HERBERT PALME, HANS-PETER GAIL) ............................................................................................. 560 
4.4.1 	Introduction .....................................................................................................................  560 

4.4.1.1 	Historical remarks............................................................................................................  560 

4.4.1.2 	Solar System matter .........................................................................................................  561 

4.4.1.3 	Classification of Solar System materials.......................................................................... 562 

4.4.1.4 	Condensation temperatures..............................................................................................  563 

4.4.2 	Chondritic meteorites .......................................................................................................  563 

4.4.2.1 	Components of chondritic meteorites .............................................................................. 563 

4.4.2.2 	Chemical variations in chondritic meteorites and the significance of CI-chondrites ....... 565 

4.4.3 	Meteorite derived Solar System abundances ................................................................... 567 

4.4.3.1 	CI-meteorites as a standard for Solar System abundances............................................... 567 

4.4.3.2 	Abundances of the elements in CI-chondrites.................................................................. 568 

4.4.3.3 	Comparison with other abundance tables ........................................................................ 573 

4.4.4 	Photospheric abundances................................................................................................. 574 

4.4.5 	Comparison of photospheric and meteoritic abundances ................................................. 578 

4.4.6 	Solar System abundances................................................................................................. 583 

4.4.6.1 	Recommended present-day solar abundances.................................................................. 583 

4.4.6.2 	Mass fractions X, Y, and Z in present-day solar material ................................................ 585 

4.4.6.3 	Solar System abundances 4.56 Ga ago ............................................................................ 587 

4.4.6.4 	Abundances of the nuclides .............................................................................................  587 

4.4.7 	Elemental abundances in neighboring stars in the Milky Way ........................................ 592 

4.4.8 	References for 4.4 ............................................................................................................  595 

4.5 	Chronology of the solar system (MARIO TRIELOFF) ......................................................... 599 

4.5.1 	Definitions and principles of age determinations based on radioisotopes........................ 599 

4.5.2 The age of the Solar System: from dust to planets........................................................... 600 

4.5.2.1 The formation process of planetary systems.................................................................... 600 

4.5.2.2 Formation and age of first Solar System solids................................................................ 601 

4.5.2.3 Formation and age of asteroid sized planetesimals.......................................................... 602 

4.5.2.4 Formation and age of planets...........................................................................................  605 

4.5.3 Secondary history: collisions, impact cratering, and magmatic activity on large bodies . 607 
4.5.4 References for 4.5 ............................................................................................................  608

 Color-picture part ............................................................................................................ 613 

