作者君在作品相关中其实已经解释过这个问题。

    不过仍然有人质疑——“你说得太含糊了”，“火星轨道的变化比你想象要大得多！”

    那好吧，既然作者君的简单解释不够有力，那咱们就看看严肃的东西，反正这本书写到现在，嚷嚷着本书bug一大堆，用初高中物理在书中挑刺的人也不少。

    以下是文章内容：

    long-teringunstablewhenacloseencounteroccurssoprehensive，butitseeputationprocesses.inrelationtothis，wisdoparetheseintegrationssipletedallthecalculations.seesection4.1forparedtheresultofourparethetestintegrationwiththeposedintofrequencycoponentperunitpletelylinear，theorbitalenergyandtheangularponentoftheinnerfourplanetscalculatedfroparedwiththoseoftheouterjovianplanets.anotherthingwenoticeisthattheinnerplanetarysubsysteeunstableparedwiththatofthevenus–earthpair.

    5±5x1010-yrintegrationsofouterplanetaryorbits

    sincethejovianplanetaryeszero，i.e.thelongitudesofascendingnodesofneptuneandplutooverlap，theinclinationofplutobecoeses90°.whenθ3becoeseses90°again.williams&bensonanticipatedthistypeofresonance，laterconfirmedbymilani，nobili&carpino.

    anargumentθ4=?p??n+3libratesaround180°withalongperiod，～5.7x108yr.

    inournumericalintegrations，theresonances–arewellmaintained，andvariationofthecriticalargumentsθ1，θ2，θ3remainsimilarduringthewholeintegrationperiod.however，thefourthresonanceappearstobedifferent:thecriticalargumentθ4alternateslibrationandcirculationovera1010-yrtime-scale.thisisaninterestingfactthatkinoshita&nakai'sshorterintegrationswerenotabletodisclose.

    6discussion

    whatkindofdynamicalmechanismmaintainsthislong-termstabilityoftheplanetarysystem?wecanimmediatelythinkoftwomajorfeaturesthatmayberesponsibleforthelong-termstability.first，thereseemtobenosignificantlower-orderresonancesbetweenanypairamongthenineplanets.jupiterandsaturnareclosetoa5:2meanmotionresonance，butnotjustintheresonancezone.higher-orderresonancesmaycausethechaoticnatureoftheplanetarydynamicalmotion，buttheyarenotsostrongastodestroythestableplanetarymotionwithinthelifetimeoftherealsolarsystem.thesecondfeature，whichwethinkismoreimportantforthelong-termstabilityofourplanetarysystem，isthedifferenceindynamicaldistancebetweenterrestrialandjovianplanetarysubsystems.whenwemeasureplanetaryseparationsbythemutualhillradii，separationsamongterrestrialplanetsaregreaterthan26rh，whereasthoseamongjovianplanetsarelessthan14rh.thisdifferenceisdirectlyrelatedtothedifferencebetweendynamicalfeaturesofterrestrialandjovianplanets.terrestrialplanetshavesmallermasses，shorterorbitalperiodsandwiderdynamicalseparation.theyarestronglyperturbedbyjovianplanetsthathavelargermasses，longerorbitalperiodsandnarrowerdynamicalseparation.jovianplanetsarenotperturbedbyanyothermassivebodies.

    thepresentterrestrialplanetarysystemisstillbeingdisturbedbythemassivejovianplanets.however，thewideseparationandmutualinteractionamongtheterrestrialplanetsrendersthedisturbanceineffective;thedegreeofdisturbancebyjovianplanetsiso，sincethedisturbancecausedbyjovianplanetsisaforcedoscillationhavinganamplitudeofo.heighteningofeccentricity，forexampleo～0.05，isfarfromsufficienttoprovokeinstabilityintheterrestrialplanetshavingsuchawideseparationas26rh.thusweassumethatthepresentwidedynamicalseparationamongterrestrialplanetsisprobablyoneofthemostsignificantconditionsformaintainingthestabilityoftheplanetarysystemovera109-yrtime-span.ourdetailedanalysisoftherelationshipbetweendynamicaldistancebetweenplanetsandtheinstabilitytime-scaleofsolarsystemplanetarymotionisnowon-going.

    althoughournumericalintegrationsspanthelifetimeofthesolarsystem，thenumberofintegrationsisfarfromsufficienttofilltheinitialphasespace.itisnecessarytoperformmoreandmorenumericalintegrationstoconfirmandexamineindetailthelong-termstabilityofourplanetarydynamics.

    ——以上文段引自ito，t.&tanikawa，k.long-termintegrationsandstabilityofplanetaryorbitsinoursolarsystem.mon.not.r.astron.soc.336，483–500

    这只是作者君参考的一篇文章，关于太阳系的稳定性。

    还有其他论文，不过也都是英文的，相关课题的中文文献很少，那些论文下载一篇要九美元（《nature》真是暴利），作者君写这篇文章的时候已经回家，不在检测中心，所以没有数据库的使用权，下不起，就不贴上来了。