第76章 对火星轨道变化问题的最后解释 (第10/12页)

ialplaarysubsystem.

    itisnotclearatthemomentwhythevehpairexhibitsaivecorrelationinenergyexgeand'itivecorrelationinangularmomentumexge.ossiblyexplainthisthroughthegeneralfactthattherearenoseculartermsinplaarysemimajoraxesuptosed-orderperturbationtheories(cf.brouwerboccalettipucacco1998).thismeansthattheplaaryorbitalenergy(whichisdirectlyrelatedtothesemimajoraxisa)mightbemuchlessaffectedbyperturbingplahanistheangularmomentumexge(whichrelatestoe).heheetricitiesofvenusahbedisturbedeasilybyjupiterandsaturn，whichresultsin'itivecorrelationintheangularmomentumexge.oherhand，thesemimajoraxesofvenusaharelesslikelytobedisturbedbythejovianplahustheenergyexgemaybelimitedonlywithinthevehpair，whichresultsiivecorrelationintheexgeoforbitalenergyinthepair.

    asfortheouterjovianplaarysubsystem，jupiter–saturnanduranus–uomakedynamicalpairs.however，thestrenhoftheircouplingisnotasstrongparedwiththatofthevehpair.

    5±5x1010-yriionsofouterplaaryorbits

    sihejovianplaarymassesaremuchlargerthaerrestrialplaarymasses，wetreatthejovianplaarysystemasanindepeplaarysystemintermsofthestudyofitsdynamicalstability.hence，weaddedacoupleoftrialiionsthatspan±5x1010yr，includingonlytheouterfiveplahefourjovianplaspluspluto).theresultsexhibittherigorousstabilityoftheouterplaarysystemoverthislongtime-span.orbitalfigurations(fig.12)，andvariationofetricitiesandinations(fig.13)showthisveryloabilityoftheouterfiveplasinboththetimeandthefrequenains.althoughwedonotshoshere，thetypicalfrequencyoftheorbitaloscillationofplutoaherouterplasisalmoststantduringtheseverylong-termiionperiods，whichisdemonstratediime–frequencymapsonourwebpage.

    iwoiions，therelativenumericalerrorialenergywas～10?6andthatofthetotalangularmomentumwas～10?10.

    5.1resoheune–plutosystem

    kinoshitanakai(1996)iedtheouterfiveplaaryorbitsover±5.5x109yr.theyfoundthatfourmajorresoweeuneandplutoaremaintainedduringthewholeiionperiod，andthattheresonancesmaybethemaincausesofthestabilityof