▁Nice ▁model , ▁after ▁the ▁formation ▁of ▁the ▁Sol ar ▁System , ▁the ▁or bits ▁of ▁all ▁the ▁giant ▁plan ets ▁continued ▁to ▁change ▁slowly , ▁influenced ▁by ▁their ▁interaction ▁with ▁the ▁large ▁number ▁of ▁remaining ▁plan etes im als . ▁After ▁ 5 0 0 – 6 0 0   mill ion ▁years ▁( about ▁ 4   b ill ion ▁years ▁ago ) ▁Jup iter ▁and ▁Sat urn ▁fell ▁into ▁a ▁ 2 : 1 ▁reson ance : ▁Sat urn ▁orb ited ▁the ▁Sun ▁once ▁for ▁every ▁two ▁Jup iter ▁or bits . ▁This ▁reson ance ▁created ▁a ▁gravit ational ▁push ▁against ▁the ▁outer ▁plan ets , ▁possibly ▁causing ▁Ne pt une ▁to ▁sur ge ▁past ▁U ran us ▁and ▁pl ough ▁into ▁the ▁ancient ▁K ui per ▁bel t . ▁The ▁plan ets ▁scattered ▁the ▁majority ▁of ▁the ▁small ▁ icy ▁bodies ▁in wards , ▁while ▁themselves ▁moving ▁out wards . ▁These ▁plan etes im als ▁then ▁scattered ▁off ▁the ▁next ▁planet ▁they ▁encountered ▁in ▁a ▁similar ▁manner , ▁moving ▁the ▁plan ets ' ▁or bits ▁out wards ▁while ▁they ▁moved ▁in wards . ▁This ▁process ▁continued ▁until ▁the ▁plan etes im als ▁interact ed ▁with ▁Jup iter , ▁whose ▁immense ▁gravity ▁sent ▁them ▁into ▁highly ▁elli pt ical ▁or bits ▁or ▁even ▁e ject ed ▁them ▁out right ▁from ▁the ▁Sol ar ▁System . ▁This ▁caused ▁Jup iter ▁to ▁move ▁slightly ▁in ward . ▁Those ▁objects ▁scattered ▁by ▁Jup iter ▁into ▁highly ▁elli pt ical ▁or bits ▁formed ▁the