第76章 对火星轨道变化问题的最后解释
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仍质疑——“太含糊”,“火星轨变化比想象!”
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以文章内容:
lng-terintegratinsandstabilityfplanetaryrbitsinurslarsyste
abstrat
epresenttheresultsfverylng-ternuerialintegratinsfplanetaryrbitaltinsver109-yrtie-spansinludingallnineplanets.aquikinspetinfurnuerialdatashsthattheplanetarytin,atleastinursipledynaialdel,seestbequitestableevenverthisverylngtie-span.alserlkatthelest-frequenysillatinsusingal-passfiltershsustheptentiallydiffusiveharaterfterrestrialplanetarytin,espeiallythatferury.thebehaviurftheeentriityferuryinurintegratinsisqualitativelysiilarttheresultsfrjaqueslaskar'sseularperturbatinthery(e.g.eax~0.35ver~±4gyr).hever,therearenapparentseularinreasesfeentriityrinlinatininanyrbitaleleentsftheplanets,hihayberevealedbystilllnger-ternuerialintegratins.ehavealsperfredaupleftrialintegratinsinludingtinsftheuterfiveplanetsvertheduratinf±5x1010yr.theresultindiatesthatthethreeajrresnanesintheneptune–plutsystehavebeenaintainedverthe1011-yrtie-span.
1intrdutin
1.1definitinftheprble
thequestinfthestabilityfurslarsystehasbeendebatedverseveralhundredyears,sinetheerafnetn.theprblehasattratedanyfausatheatiiansvertheyearsandhasplayedaentralrleinthedevelpentfnn-lineardynaisandhasthery.hever,edntyethaveadefiniteansertthequestinfhetherurslarsysteisstablernt.thisispartlyaresultfthefatthatthedefinitinftheter‘stability’isvaguehenitisusedinrelatinttheprblefplanetarytinintheslarsyste.atuallyitisnteasytgivealear,rigrusandphysiallyeaningfuldefinitinfthestabilityfurslarsyste.
anganydefinitinsfstability,hereeadptthehilldefinitin(gladan1993):atuallythisisntadefinitinfstability,butfinstability.edefineasysteasbeingunstablehenalseenunterurssehereinthesyste,startingfraertaininitialnfiguratin(habers,etherillittanikaa1999).asysteisdefinedasexperieningalseenunterhentbdiesapprahneantherithinanareafthelargerhillradius.therisethesysteisdefinedasbeingstable.henefrardestatethaturplanetarysysteisdynaiallystableifnlseenunterhappensduringtheagefurslarsyste,abut±5gyr.inidentally,thisdefinitinaybereplaedbyneinhihanurrenefanyrbitalrssingbeteeneitherfapairfplanetstakesplae.thisisbeauseeknfrexperienethatanrbitalrssingisverylikelytleadtalseenunterinplanetaryandprtplanetarysystes(yshinaga,kkubakin1999).fursethisstateentanntbesiplyappliedtsystesithstablerbitalresnanessuhastheneptune–plutsyste.
1.2previusstudiesandaisfthisresearh
inadditintthevaguenessftheneptfstability,theplanetsinurslarsysteshaharatertypialfdynaialhas(sussanisd1988,1992).theausefthishatibehaviurisnpartlyunderstdasbeingaresultfresnaneverlapping(urraylear,franklinhlan2001).hever,ituldrequireintegratingveranenseblefplanetarysystesinludingallnineplanetsfraperidveringseveral10gyrtthrughlyunderstandthelng-terevlutinfplanetaryrbits,sinehatidynaialsystesareharaterizedbytheirstrngdependeneninitialnditins.
frthatpintfvie,anyfthepreviuslng-ternuerialintegratinsinludednlytheuterfiveplanets(sussankinshitanakai1996).thisisbeausetherbitalperidsftheuterplanetsaresuhlngerthanthseftheinnerfurplanetsthatitisuheasiertfllthesystefragivenintegratinperid.atpresent,thelngestnuerialintegratinspublishedinjurnalsarethsefdunanlissauer(1998).althughtheiraintargetastheeffetfpst-ain-sequeneslarasslssnthestabilityfplanetaryrbits,theyperfredanyintegratinsveringupt~1011yrftherbitaltinsfthefurjvianplanets.theinitialrbitaleleentsandassesfplanetsarethesaeasthsefurslarsysteindunanlissauer'spaper,buttheydereasetheassfthesungraduallyintheirnuerialexperients.thisisbeausetheynsidertheeffetfpst-ain-sequeneslarasslssinthepaper.nsequently,theyfundthattherssingtie-salefplanetaryrbits,hihanbeatypialindiatrftheinstabilitytie-sale,isquitesensitivettheratefassdereasefthesun.hentheassfthesunislsetitspresentvalue,thejvianplanetsreainstablever1010yr,rperhapslnger.dunanlissaueralsperfredfursiilarexperientsntherbitaltinfsevenplanets(venustneptune),hihveraspanf~109yr.theirexperientsnthesevenplanetsarentyetprehensive,butitseesthattheterrestrialplanetsalsreainstableduringtheintegratinperid,aintainingalstregularsillatins.
nthetherhand,inhisauratesei-analytialseularperturbatinthery(laskar1988),laskarfindsthatlargeandirregularvariatinsanappearintheeentriitiesandinlinatinsftheterrestrialplanets,espeiallyferuryandarsnatie-salefseveral109yr(laskar1996).theresultsflaskar'sseularperturbatintheryshuldbenfiredandinvestigatedbyfullynuerialintegratins.
inthispaperepresentpreliinaryresultsfsixlng-ternuerialintegratinsnallnineplanetaryrbits,veringaspanfseveral109yr,andfttherintegratinsveringaspanf±5x1010yr.thettalelapsedtiefrallintegratinsisrethan5yr,usingseveraldediatedpsandrkstatins.nefthefundaentalnlusinsfurlng-terintegratinsisthatslarsysteplanetarytinseestbestableintersfthehillstabilityentinedabve,atleastveratie-spanf±4gyr.atually,inurnuerialintegratinsthesysteasfarrestablethanhatisdefinedbythehillstabilityriterin:ntnlydidnlseenunterhappenduringtheintegratinperid,butalsalltheplanetaryrbitaleleentshavebeennfinedinanarrreginbthintieandfrequenydain,thughplanetarytinsaresthasti.sinethepurpsefthispaperistexhibitandvervietheresultsfurlng-ternuerialintegratins,eshtypialexaplefiguresasevideneftheverylng-terstabilityfslarsysteplanetarytin.frreadershhaverespeifianddeeperinterestsinurnuerialresults,ehavepreparedaebpage(aess),hereeshrarbitaleleents,theirl-passfilteredresults,variatinfdelaunayeleentsandangularentudefiit,andresultsfursipletie–frequenyanalysisnallfurintegratins.
insetin2ebrieflyexplainurdynaialdel,nuerialethdandinitialnditinsusedinurintegratins.setin3isdevtedtadesriptinfthequikresultsfthenuerialintegratins.verylng-terstabilityfslarsysteplanetarytinisapparentbthinplanetarypsitinsandrbitaleleents.arughestiatinfnuerialerrrsisalsgiven.setin4gesntadisussinfthelngest-tervariatinfplanetaryrbitsusingal-passfilterandinludesadisussinfangularentudefiit.insetin5,epresentasetfnuerialintegratinsfrtheuterfiveplanetsthatspans±5x1010yr.insetin6ealsdisussthelng-terstabilityftheplanetarytinanditspssibleause.
2desriptinfthenuerialintegratins
(本部涉及比较复杂积计算,君贴,贴点功显示。)
2.3nuerialethd
eutilizeasend-rderisd–hlansypletiapasurainintegratinethd(isdkinshita,yshidanakai1991)ithaspeialstart-uppreduretreduethetrunatinerrrfanglevariables,‘arstart’(sahatreaine1992,1994).
thestepsizefrthenuerialintegratinsis8dthrughutallintegratinsfthenineplanets(n±1,2,3),hihisabut111ftherbitalperidftheinnerstplanet(erury).asfrthedeterinatinfstepsize,epartlyfllthepreviusnuerialintegratinfallnineplanetsinsussanisd(1988,7.2d)andsahatreaine(1994,22532d).erundedthedeialpartfthetheirstepsizest8takethestepsizeaultiplef2inrdertreduetheauulatinfrund-fferrrintheputatinpresses.inrelatintthis,isdhlan(1991)perfrednuerialintegratinsftheuterfiveplanetaryrbitsusingthesypletiapithastepsizef400d,110.83ftherbitalperidfjupiter.theirresultseestbeaurateenugh,hihpartlyjustifiesurethdfdeteriningthestepsize.hever,sinetheeentriityfjupiter(~0.05)isuhsallerthanthatferury(~0.2),eneedseareheneparetheseintegratinssiplyintersfstepsizes.
intheintegratinftheuterfiveplanets(f±),efixedthestepsizeat400d.
eadptgauss'fandgfuntinsinthesypletiaptgetheriththethird-rderhalleyethd(danby1992)asaslverfrkeplerequatins.thenuberfaxiuiteratinsesetinhalley'sethdis15,buttheyneverreahedtheaxiuinanyfurintegratins.
theintervalfthedatautputis200000d(~547yr)frthealulatinsfallnineplanets(n±1,2,3),andabut8000000d(~21903yr)frtheintegratinftheuterfiveplanets(f±).
althughnutputfilteringasdnehenthenuerialintegratinsereinpress,eappliedal-passfilterttherarbitaldataafterehadpletedallthealulatins.seesetin4.1frredetail.
2.4errrestiatin
2.4.1relativeerrrsinttalenergyandangularentu
ardingtnefthebasiprpertiesfsypletiintegratrs,hihnservethephysiallynservativequantitiesell(ttalrbitalenergyandangularentu),urlng-ternuerialintegratinsseethavebeenperfredithverysallerrrs.theaveragedrelativeerrrsfttalenergy(~10?9)andfttalangularentu(~10?11)havereainednearlynstantthrughuttheintegratinperid(fig.1).thespeialstartuppredure,arstart,uldhavereduedtheaveragedrelativeerrrinttalenergybyabutnerderfagnituderre.
relativenuerialerrrfthettalangularentuδaa0andthettalenergyδee0inurnuerialintegratinsn±1,2,3,hereδeandδaaretheabslutehangefthettalenergyandttalangularentu,respetively,ande0anda0aretheirinitialvalues.thehrizntalunitisgyr.
ntethatdifferentperatingsystes,differentatheatiallibraries,anddifferenthardarearhiteturesresultindifferentnuerialerrrs,thrughthevariatinsinrund-fferrrhandlingandnuerialalgriths.intheupperpanelffig.1,eanregnizethissituatinintheseularnuerialerrrinthettalangularentu,hihshuldberigruslypreserveduptahine-epreisin.
2.4.2errrinplanetarylngitudes
sinethesypletiapspreservettalenergyandttalangularentufn-bdydynaialsystesinherentlyell,thedegreeftheirpreservatinayntbeagdeasureftheaurayfnuerialintegratins,espeiallyasaeasurefthepsitinalerrrfplanets,i.e.theerrrinplanetarylngitudes.testiatethenuerialerrrintheplanetarylngitudes,eperfredthefllingpredures.eparedtheresultfurainlng-terintegratinsithsetestintegratins,hihspanuhshrterperidsbutithuhhigherauraythantheainintegratins.frthispurpse,eperfredauhreaurateintegratinithastepsizef0.125d(164ftheainintegratins)spanning3x105yr,startingiththesaeinitialnditinsasinthen?1integratin.ensiderthatthistestintegratinprvidesusitha‘pseud-true’slutinfplanetaryrbitalevlutin.next,eparethetestintegratiniththeainintegratin,n?1.frtheperidf3x105yr,eseeadiffereneineananaliesftheearthbeteenthetintegratinsf~0.52°(intheasefthen?1integratin).thisdiffereneanbeextraplatedtthevalue~8700°,abut25rtatinsfearthafter5gyr,sinetheerrrflngitudesinreaseslinearlyithtieinthesypletiap.siilarly,thelngitudeerrrfplutanbeestiatedas~12°.thisvaluefrplutisuhbetterthantheresultinkinshitanakai(1996)herethediffereneisestiatedas~60°.
3nuerialresults–i.glaneattheradata
inthissetinebrieflyreviethelng-terstabilityfplanetaryrbitaltinthrughsesnapshtsfranuerialdata.therbitaltinfplanetsindiateslng-terstabilityinallfurnuerialintegratins:nrbitalrssingsnrlseenuntersbeteenanypairfplanetstkplae.
3.1generaldesriptinfthestabilityfplanetaryrbits
first,ebrieflylkatthegeneralharaterfthelng-terstabilityfplanetaryrbits.urinterestherefusespartiularlyntheinnerfurterrestrialplanetsfrhihtherbitaltie-salesareuhshrterthanthseftheuterfiveplanets.aseanseelearlyfrtheplanarrbitalnfiguratinsshninfigs2and3,rbitalpsitinsftheterrestrialplanetsdifferlittlebeteentheinitialandfinalpartfeahnuerialintegratin,hihspansseveralgyr.theslidlinesdentingthepresentrbitsftheplanetsliealstithinthesarfdtseveninthefinalpartfintegratins(b)and(d).thisindiatesthatthrughuttheentireintegratinperidthealstregularvariatinsfplanetaryrbitaltinreainnearlythesaeastheyareatpresent.
vertialviefthefurinnerplanetaryrbits(frthez-axisdiretin)attheinitialandfinalpartsftheintegratinsn±1.theaxesunitsareau.thexy-planeissetttheinvariantplanefslarsystettalangularentu.(a)theinitialpartfn+1(t=0t0.0547x109yr).(b)thefinalpartfn+1(t=4.9339x108t4.9886x109yr).()theinitialpartfn?1(t=0t?0.0547x109yr).(d)thefinalpartfn?1(t=?3.9180x109t?3.9727x109yr).ineahpanel,attalf23684pintsareplttedithanintervalfabut2190yrver5.47x107yr.slidlinesineahpaneldentethepresentrbitsfthefurterrestrialplanets(takenfrde245).
thevariatinfeentriitiesandrbitalinlinatinsfrtheinnerfurplanetsintheinitialandfinalpartftheintegratinn+1isshninfig.4.asexpeted,theharaterfthevariatinfplanetaryrbitaleleentsdesntdiffersignifiantlybeteentheinitialandfinalpartfeahintegratin,atleastfrvenus,earthandars.theeleentsferury,espeiallyitseentriity,seethangetasignifiantextent.thisispartlybeausetherbitaltie-saleftheplanetistheshrtestfalltheplanets,hihleadstarerapidrbitalevlutinthantherplanets;theinnerstplanetaybenearesttinstability.thisresultappearstbeinseagreeentithlaskar's(1994,1996)expetatinsthatlargeandirregularvariatinsappearintheeentriitiesandinlinatinsferurynatie-salefseveral109yr.hever,theeffetfthepssibleinstabilityftherbitferuryayntfatallyaffettheglbalstabilityfthehleplanetarysysteingtthesallassferury.eillentinbrieflythelng-terrbitalevlutinferurylaterinsetin4usingl-passfilteredrbitaleleents.
therbitaltinftheuterfiveplanetsseesrigruslystableandquiteregularverthistie-span(seealssetin5).
3.2tie–frequenyaps
althughtheplanetarytinexhibitsverylng-terstabilitydefinedasthenn-existeneflseenunterevents,thehatinaturefplanetarydynaisanhangethesillatryperidandaplitudefplanetaryrbitaltingraduallyversuhlngtie-spans.evensuhslightflutuatinsfrbitalvariatininthefrequenydain,partiularlyintheasefearth,anptentiallyhaveasignifianteffetnitssurfaeliatesystethrughslarinslatinvariatin(f.berger1988).
tgiveanverviefthelng-terhangeinperidiityinplanetaryrbitaltin,eperfredanyfastfuriertransfratins(ffts)alngthetieaxis,andsuperpsedtheresultingperidgrastdrat-diensinaltie–frequenyaps.thespeifiapprahtdraingthesetie–frequenyapsinthispaperisverysiple–uhsiplerthantheaveletanalysisrlaskar's(1990,1993)frequenyanalysis.
dividethel-passfilteredrbitaldataintanyfragentsfthesaelenh.thelenhfeahdatasegentshuldbeaultiplef2inrdertapplythefft.
eahfragentfthedatahasalargeverlappingpart:frexaple,hentheithdatabeginsfrt=tiandendsatt=ti+t,thenextdatasegentrangesfrti+δt≤ti+δt+t,hereδt?t.entinuethisdivisinuntilereahaertainnubernbyhihtn+treahesthettalintegratinlenh.
eapplyanfftteahfthedatafragents,andbtainnfrequenydiagras.
ineahfrequenydiagrabtainedabve,thestrenhfperidiityanbereplaedbyagrey-sale(rlur)hart.
eperfrthereplaeent,andnnetallthegrey-sale(rlur)hartsintnegraphfreahintegratin.thehrizntalaxisfthesenegraphsshuldbethetie,i.e.thestartingtiesfeahfragentfdata(ti,herei=1,…,n).thevertialaxisrepresentstheperid(rfrequeny)fthesillatinfrbitaleleents.
ehaveadptedanfftbeausefitsverhelingspeed,sinetheauntfnuerialdatatbedepsedintfrequenypnentsisterriblyhuge(severaltensfgbytes).
atypialexaplefthetie–frequenyapreatedbytheabvepreduresisshninagrey-salediagraasfig.5,hihshsthevariatinfperidiityintheeentriityandinlinatinfearthinn+2integratin.infig.5,thedarkareashsthatatthetieindiatedbythevaluentheabsissa,theperidiityindiatedbytherdinateisstrngerthaninthelighterareaarundit.eanregnizefrthisapthattheperidiityftheeentriityandinlinatinfearthnlyhangesslightlyvertheentireperidveredbythen+2integratin.thisnearlyregulartrendisqualitativelythesaeintherintegratinsandfrtherplanets,althughtypialfrequeniesdifferplanetbyplanetandeleentbyeleent.
4.2lng-terexhangefrbitalenergyandangularentu
ealulateverylng-peridivariatinandexhangefplanetaryrbitalenergyandangularentuusingfiltereddelaunayeleentsl,g,h.gandhareequivalentttheplanetaryrbitalangularentuanditsvertialpnentperunitass.lisrelatedttheplanetaryrbitalenergyeperunitassase=?μ22l2.ifthesysteispletelylinear,therbitalenergyandtheangularentuineahfrequenybinustbenstant.nn-linearityintheplanetarysysteanauseanexhangefenergyandangularentuinthefrequenydain.theaplitudefthelest-frequenysillatinshuldinreaseifthesysteisunstableandbreaksdngradually.hever,suhasyptfinstabilityisntprinentinurlng-terintegratins.
infig.7,thettalrbitalenergyandangularentufthefurinnerplanetsandallnineplanetsareshnfrintegratinn+2.theupperthreepanelsshthelng-peridivariatinfttalenergy(dentedase-e0),ttalangularentu(g-g0),andthevertialpnent(h-h0)ftheinnerfurplanetsalulatedfrthel-passfiltereddelaunayeleents.e0,g0,h0dentetheinitialvaluesfeahquantity.theabslutedifferenefrtheinitialvaluesisplttedinthepanels.thelerthreepanelsineahfigureshe-e0,g-g0andh-h0fthettalfnineplanets.theflutuatinshninthelerpanelsisvirtuallyentirelyaresultftheassivejvianplanets.
paringthevariatinsfenergyandangularentuftheinnerfurplanetsandallnineplanets,itisapparentthattheaplitudesfthseftheinnerplanetsareuhsallerthanthsefallnineplanets:theaplitudesftheuterfiveplanetsareuhlargerthanthseftheinnerplanets.thisdesnteanthattheinnerterrestrialplanetarysubsysteisrestablethantheuterne:thisissiplyaresultftherelativesallnessftheassesfthefurterrestrialplanetsparediththseftheuterjvianplanets.antherthingentieisthattheinnerplanetarysubsysteaybeeunstablererapidlythantheuternebeausefitsshrterrbitaltie-sales.thisanbeseeninthepanelsdentedasinner4infig.7herethelnger-peridiandirregularsillatinsarereapparentthaninthepanelsdentedasttal9.atually,theflutuatinsintheinner4panelsaretalargeextentasaresultftherbitalvariatinftheerury.hever,eanntnegletthentributinfrtherterrestrialplanets,aseillseeinsubsequentsetins.
4.4lng-teruplingfseveralneighburingplanetpairs
letusseeseindividualvariatinsfplanetaryrbitalenergyandangularentuexpressedbythel-passfiltereddelaunayeleents.figs10and11shlng-terevlutinftherbitalenergyfeahplanetandtheangularentuinn+1andn?2integratins.entiethatseplanetsfrapparentpairsintersfrbitalenergyandangularentuexhange.inpartiular,venusandearthakeatypialpair.inthefigures,theyshnegativerrelatinsinexhangefenergyandpsitiverrelatinsinexhangefangularentu.thenegativerrelatininexhangefrbitalenergyeansthatthetplanetsfralseddynaialsysteintersftherbitalenergy.thepsitiverrelatininexhangefangularentueansthatthetplanetsaresiultaneuslyunderertainlng-terperturbatins.andidatesfrperturbersarejupiterandsaturn.alsinfig.11,eanseethatarsshs'itiverrelatinintheangularentuvariatintthevenus–earthsyste.eruryexhibitsertainnegativerrelatinsintheangularentuversusthevenus–earthsyste,hihseestbeareatinausedbythenservatinfangularentuintheterrestrialplanetarysubsyste.
itisntlearattheenthythevenus–earthpairexhibitsanegativerrelatininenergyexhangeand'itiverrelatininangularentuexhange.eaypssiblyexplainthisthrughbservingthegeneralfatthattherearenseulartersinplanetaryseiajraxesuptsend-rderperturbatintheries(f.bruerbalettipua1998).thiseansthattheplanetaryrbitalenergy(hihisdiretlyrelatedttheseiajraxisa)ightbeuhlessaffetedbyperturbingplanetsthanistheangularentuexhange(hihrelateste).hene,theeentriitiesfvenusandearthanbedisturbedeasilybyjupiterandsaturn,hihresultsin'itiverrelatinintheangularentuexhange.nthetherhand,theseiajraxesfvenusandeartharelesslikelytbedisturbedbythejvianplanets.thustheenergyexhangeaybeliitednlyithinthevenus–earthpair,hihresultsinanegativerrelatinintheexhangefrbitalenergyinthepair.
asfrtheuterjvianplanetarysubsyste,jupiter–saturnanduranus–neptuneseetakedynaialpairs.hever,thestrenhftheiruplingisntasstrngparediththatfthevenus–earthpair.
5±5x1010-yrintegratinsfuterplanetaryrbits
sinethejvianplanetaryassesareuhlargerthantheterrestrialplanetaryasses,etreatthejvianplanetarysysteasanindependentplanetarysysteintersfthestudyfitsdynaialstability.hene,eaddedaupleftrialintegratinsthatspan±5x1010yr,inludingnlytheuterfiveplanets(thefurjvianplanetsplusplut).theresultsexhibittherigrusstabilityftheuterplanetarysysteverthislngtie-span.rbitalnfiguratins(fig.12),andvariatinfeentriitiesandinlinatins(fig.13)shthisverylng-terstabilityftheuterfiveplanetsinbththetieandthefrequenydains.althughedntshapshere,thetypialfrequenyftherbitalsillatinfplutandthetheruterplanetsisalstnstantduringtheseverylng-terintegratinperids,hihisdenstratedinthetie–frequenyapsnurebpage.
inthesetintegratins,therelativenuerialerrrinthettalenergyas~10?6andthatfthettalangularentuas~10?10.
5.1resnanesintheneptune–plutsyste
kinshitanakai(1996)integratedtheuterfiveplanetaryrbitsver±5.5x109yr.theyfundthatfurajrresnanesbeteenneptuneandplutareaintainedduringthehleintegratinperid,andthattheresnanesaybetheainausesfthestabilityftherbitfplut.theajrfurresnanesfundinpreviusresearhareasflls.inthefllingdesriptin,λdentestheeanlngitude,Ωisthelngitudeftheasendingndeand?isthelngitudefperihelin.subsriptspandndenteplutandneptune.
eantinresnanebeteenneptuneandplut(3:2).theritialarguentθ1=3λp?2λn??plibratesarund180°ithanaplitudefabut80°andalibratinperidfabut2x104yr.
thearguentfperihelinfplutp=θ2=?p?Ωplibratesarund90°ithaperidfabut3.8x106yr.thedinantperidivariatinsftheeentriityandinlinatinfplutaresynhrnizediththelibratinfitsarguentfperihelin.thisisantiipatedintheseularperturbatintherynstrutedbykzai(1962).
thelngitudefthendefplutreferredtthelngitudefthendefneptune,θ3=Ωp?Ωn,irulatesandtheperidfthisirulatinisequalttheperidfθ2libratin.henθ3beeszer,i.e.thelngitudesfasendingndesfneptuneandplutverlap,theinlinatinfplutbeesaxiu,theeentriitybeesiniuandthearguentfperihelinbees90°.henθ3bees180°,theinlinatinfplutbeesiniu,theeentriitybeesaxiuandthearguentfperihelinbees90°again.illiasbensn(1971)antiipatedthistypefresnane,laternfiredbyilani,nbiliarpin(1989).
anarguentθ4=?p??n+3(Ωp?Ωn)libratesarund180°ithalngperid,~5.7x108yr.
inurnuerialintegratins,theresnanes(i)–(iii)areellaintained,andvariatinftheritialarguentsθ1,θ2,θ3reainsiilarduringthehleintegratinperid(figs14–16).hever,thefurthresnane(iv)appearstbedifferent:theritialarguentθ4alternateslibratinandirulatinvera1010-yrtie-sale(fig.17).thisisaninterestingfatthatkinshitanakai's(1995,1996)shrterintegratinserentabletdislse.
6disussin
hatkindfdynaialehanisaintainsthislng-terstabilityftheplanetarysyste?eaniediatelythinkftajrfeaturesthatayberespnsiblefrthelng-terstability.first,thereseetbensignifiantler-rderresnanes(eantinandseular)beteenanypairangthenineplanets.jupiterandsaturnarelseta5:2eantinresnane(thefaus‘greatinequality’),butntjustintheresnanezne.higher-rderresnanesayausethehatinatureftheplanetarydynaialtin,buttheyarentsstrngastdestrythestableplanetarytinithinthelifetieftherealslarsyste.thesendfeature,hihethinkisreiprtantfrthelng-terstabilityfurplanetarysyste,isthediffereneindynaialdistanebeteenterrestrialandjvianplanetarysubsystes(ittanikaa1999,2001).heneeasureplanetaryseparatinsbytheutualhillradii(r_),separatinsangterrestrialplanetsaregreaterthan26rh,hereasthseangjvianplanetsarelessthan14rh.thisdiffereneisdiretlyrelatedtthedifferenebeteendynaialfeaturesfterrestrialandjvianplanets.terrestrialplanetshavesallerasses,shrterrbitalperidsandiderdynaialseparatin.theyarestrnglyperturbedbyjvianplanetsthathavelargerasses,lngerrbitalperidsandnarrerdynaialseparatin.jvianplanetsarentperturbedbyanytherassivebdies.
thepresentterrestrialplanetarysysteisstillbeingdisturbedbytheassivejvianplanets.hever,theideseparatinandutualinteratinangtheterrestrialplanetsrendersthedisturbaneineffetive;thedegreefdisturbanebyjvianplanetsis(ej)(rderfagnitudeftheeentriityfjupiter),sinethedisturbaneausedbyjvianplanetsisafredsillatinhavinganaplitudef(ej).heighteningfeentriity,frexaple(ej)~0.05,isfarfrsuffiienttprvkeinstabilityintheterrestrialplanetshavingsuhaideseparatinas26rh.thuseassuethatthepresentidedynaialseparatinangterrestrialplanets(;26rh)isprbablynefthestsignifiantnditinsfraintainingthestabilityftheplanetarysystevera109-yrtie-span.urdetailedanalysisftherelatinshipbeteendynaialdistanebeteenplanetsandtheinstabilitytie-salefslarsysteplanetarytinisnn-ging.
althughurnuerialintegratinsspanthelifetieftheslarsyste,thenuberfintegratinsisfarfrsuffiienttfilltheinitialphasespae.itisneessarytperfrreandrenuerialintegratinstnfirandexaineindetailthelng-terstabilityfurplanetarydynais.
——以文段引it,t.tanikaa,k.lng-terintegratinsandstabilityfplanetaryrbitsinurslarsyste.n.nt.r.astrn.s.336,483–500(2002)
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论文,英文,相关课题文文献很少,些论文载篇九美元(《nature》真暴利),君写篇文章候已回,检测,以数据库使权,,贴。