天文学英文版PPT资料 (13)

UniverseEighthEditionRogerA.Freedman•WilliamJ.KaufmannIIICHAPTER12&13Jupiter,SaturnandtheirMoonsOnlineQuizfromChapter11dueWednesday10/20OnlineQuizfromChapter12,13,14dueMonday10/25(relax,Ch.14isprettyshort).SkipChapter15(“VagabondsoftheSolarSystem”)ExamIInowonWednesday10/27(Ch.7-14).HalfofthelectureperiodMonday10/25willbedevotedtocomprehensivereviewlikelasttime.HWandExamIIWheredoestheenergyformotionintheatmospheresofJupiterandSaturncomefrom?A.HeatfromtheSunB.EnergyfromthesolarwindC.TidalinteractionswiththeirlargemoonsD.HeatrisingfromtheinterioroftheseplanetsE.ThemagneticfieldsoftheplanetsQ12.11WheredoestheenergyformotionintheatmospheresofJupiterandSaturncomefrom?A.HeatfromtheSunB.EnergyfromthesolarwindC.TidalinteractionswiththeirlargemoonsD.HeatrisingfromtheinterioroftheseplanetsE.ThemagneticfieldsoftheplanetsA12.11WhatistheoriginofthemagneticfieldsofJupiterandSaturn?A.Thethickhydrogenlayerisundersomuchpressurethatitbecomesaconductingliquidabletogenerateamagneticfield.B.Alarge,solidironcoredeepinsidetheseplanetsgeneratesamagneticfield.C.Electriccurrentsflowinlarge,conductingironcoremeltedbythetremendousheat.D.SolarwindsfromtheSungeneratethestrongmagneticfield.E.Thesolarwindinteractswiththehydrogenatmosphere.Q12.9WhatistheoriginofthemagneticfieldsofJupiterandSaturn?A.Thethickhydrogenlayerisundersomuchpressurethatitbecomesaconductingliquidabletogenerateamagneticfield.B.Alarge,solidironcoredeepinsidetheseplanetsgeneratesamagneticfield.C.Electriccurrentsflowinlarge,conductingironcoremeltedbythetremendousheat.D.SolarwindsfromtheSungeneratethestrongmagneticfield.E.Thesolarwindinteractswiththehydrogenatmosphere.A12.9TheheatingoftheGalileansatellitesofJupiterleadstogeologicallyactivesurfaces.Whichoneofthefollowingbestexplainsthesourceofheat?A.Asasatelliterotatesonitsaxis,it“flexes”duetothenearbytidalforcesofJupiter.Thefrictionthataccompaniestheflexingcreatesheat.B.AsthesatellitechangesitsdistancefromJupiterinitsellipticalorbit,it“flexes”duetothetidalforcesofJupiter.Thefrictionthataccompaniestheflexingcreatesheat.C.Jupiter’sintensemagneticfieldheatsuptheconductingcoreofthesatellite.D.Theheatisleftoverfromtheformationofthesatellites.E.Interactionswiththesolarwindcausetheheat.Q13.5TheheatingoftheGalileansatellitesofJupiterleadstogeologicallyactivesurfaces.Whichoneofthefollowingbestexplainsthesourceofheat?A.Asasatelliterotatesonitsaxis,it“flexes”duetothenearbytidalforcesofJupiter.Thefrictionthataccompaniestheflexingcreatesheat.B.AsthesatellitechangesitsdistancefromJupiterinitsellipticalorbit,it“flexes”duetothetidalforcesofJupiter.Thefrictionthataccompaniestheflexingcreatesheat.C.Jupiter’sintensemagneticfieldheatsuptheconductingcoreofthesatellite.D.Theheatisleftoverfromtheformationofthesatellites.E.Interactionswiththesolarwindcausetheheat.A13.5Jupiter’ssatelliteGanymedehasnoatmosphere,whereasSaturn’ssatelliteTitanhasasignificantatmosphere.ThisisbecauseA.GanymedeismuchsmallerthanTitanandthuscannotretainanatmosphere.B.GanymedeisclosertotheSunandwarmerthanTitan,soanyatmospherewouldescapeintospace.C.Ganymedeisinactive,whereasTitanisactivewithvolcanoescontinuallyreplenishingitsatmosphere.D.TitaniscloseenoughtoSaturnthatgasesleakfromthisplanetontoit.GanymedeistoofarfromJupiterforthistohappen.Q13.13Jupiter’ssatelliteGanymedehasnoatmosphere,whereasSaturn’ssatelliteTitanhasasignificantatmosphere.ThisisbecauseA.GanymedeismuchsmallerthanTitanandthuscannotretainanatmosphere.B.GanymedeisclosertotheSunandwarmerthanTitan,soanyatmospherewouldescapeintospace.C.Ganymedeisinactive,whereasTitanisactivewithvolcanoescontinuallyreplenishingitsatmosphere.D.TitaniscloseenoughtoSaturnthatgasesleakfromthisplanetontoit.GanymedeistoofarfromJupiterforthistohappen.A13.13KeyIdeasCompositionandStructure:JupiterandSaturnarebothmuchlargerthanEarth.Eachiscomposedof71%hydrogen,24%helium,and5%allotherelementsbymass.BothplanetshaveahigherpercentageofheavyelementsthandoestheSun.JupiterprobablyhasarockycoreseveraltimesmoremassivethantheEarth.Thecoreissurroundedbyalayerofliquid“ices”(water,ammonia,methane,andassociatedcompounds).Ontopofthisisalayerofheliumandliquidmetallichydrogenandanoutermostlayercomposedprimarilyofordinaryhydrogenandhelium.AllofJupiter’svisiblefeaturesarenearthetopofthisoutermostlayer.KeyIdeasSaturn’sinternalstructureissimilartothatofJupiter,butitscoremakesupalargerfractionofitsvolumeanditsliquidmetallichydrogenmantleisshallowerthanthatofJupiter.JupiterandSaturnbothrotatesorapidlythattheplanetsarenoticeablyflattened.Therotationofbothplanets’interiorsisrevealedbyvariationsintheradioemissionsfromtheplanets.BothJupiterandSaturnemitmoreenergythantheyreceivefromtheSun.Presumablybothplanetsarestillcooling.KeyIdeasAtmospheres:Thevisible“surfaces”ofJupiterandSaturnareactuallythetopsoftheirclouds.Therapidrotationoftheplanetstwiststhecloudsintodarkbeltsandlightzonesthatrunparalleltotheequator.Strongzonalwindsrunalongthebeltsandzones.Theouterlayersofbothplanets’atmospheresshowdifferentialrotation:Theequatorialregionsrotateslightlyfasterthanthepol