pair aong the ne plas jupiter and saturn are close to a 5:2 an otion renance (the fao &l;great eality&r;)， but not jt the renance zone higher-order renances ay cae the 插otic nature of the plaary dynaical otion， but they are not strong as to destroy the stable plaary otion with the lifeti of the real lar syste the send feature， which we thk is ore iportant for the long-ter stability of our plaary syste， is the difference dynaical distance beeen terrestrial and jovian plaary subsystes (ito ≈ap; tanikawa 1999， 2001) when we asure plaary separations by the utual hill radii (r_)， separations aong terrestrial plas are greater than 26rh， whereas those aong jovian plas are less than 14rh this difference is directly related to the difference beeen dynaical features of terrestrial and jovian plas terrestrial plas have saller asses， shorter orbital periods and wider dynaical separation they are strongly perturbed by jovian plas that have larr asses， lonr orbital periods and narrower dynaical separation jovian plas are not perturbed by any other assive bodies

the present terrestrial plaary syste is still beg disturbed by the assive jovian plas however， the wide separation and utual teraction aong the terrestrial plas renders the disturbance effective; the degree of disturbance by jovian plas is o(ej)(order of agnitude of the eentricity of jupiter)， sce the disturbance caed by jovian plas is a forced oscillation havg an aplitude of o(ej) heighteng of eentricity， for exaple o