etes im als ▁formed ▁there . ▁As ▁with ▁the ▁terrest ri als , ▁plan etes im als ▁in ▁this ▁region ▁later ▁co ales ced ▁and ▁formed ▁ 2 0 – 3 0 ▁Moon - ▁to ▁Mars - s ized ▁planet ary ▁emb ry os ; ▁however , ▁the ▁proxim ity ▁of ▁Jup iter ▁meant ▁that ▁after ▁this ▁planet ▁formed , ▁ 3   mill ion ▁years ▁after ▁the ▁Sun , ▁the ▁region ' s ▁history ▁changed ▁dram atically . ▁Or b ital ▁reson ances ▁with ▁Jup iter ▁and ▁Sat urn ▁are ▁particularly ▁strong ▁in ▁the ▁astero id ▁bel t , ▁and ▁gravit ational ▁interactions ▁with ▁more ▁massive ▁emb ry os ▁scattered ▁many ▁plan etes im als ▁into ▁those ▁reson ances . ▁Jup iter ' s ▁gravity ▁increased ▁the ▁velocity ▁of ▁objects ▁within ▁these ▁reson ances , ▁causing ▁them ▁to ▁sh atter ▁upon ▁collision ▁with ▁other ▁bodies , ▁rather ▁than ▁acc re te . ▁ ▁As ▁Jup iter ▁migr ated ▁in ward ▁following ▁its ▁formation ▁( see ▁Planet ary ▁migration ▁below ), ▁reson ances ▁would ▁have ▁swe pt ▁across ▁the ▁astero id ▁bel t , ▁dynamically ▁exc iting ▁the ▁region ' s ▁population ▁and ▁increasing ▁their ▁veloc ities ▁relative ▁to ▁each ▁other . ▁The ▁cum ulative ▁action ▁of ▁the ▁reson ances ▁and ▁the ▁emb ry os ▁either ▁scattered ▁the ▁plan etes im als ▁away ▁from ▁the ▁astero id ▁bel t ▁or ▁excited ▁their ▁orb ital ▁incl in ations ▁and ▁ecc ent ric ities . ▁Some ▁of ▁those ▁massive ▁emb ry os ▁too ▁were ▁e