▁( g iven ▁a ▁large ▁enough ▁impact ▁at ▁a ▁shall ow ▁angle ); ▁and ▁ ▁Capt ure ▁of ▁a ▁passing ▁object . ▁ ▁Jup iter ▁and ▁Sat urn ▁have ▁several ▁large ▁mo ons , ▁such ▁as ▁Io , ▁Europa , ▁Gan ym ede ▁and ▁T itan , ▁which ▁may ▁have ▁origin ated ▁from ▁disc s ▁around ▁each ▁giant ▁planet ▁in ▁much ▁the ▁same ▁way ▁that ▁the ▁plan ets ▁formed ▁from ▁the ▁disc ▁around ▁the ▁Sun . ▁This ▁origin ▁is ▁indicated ▁by ▁the ▁large ▁sizes ▁of ▁the ▁mo ons ▁and ▁their ▁proxim ity ▁to ▁the ▁planet . ▁These ▁attributes ▁are ▁impossible ▁to ▁achieve ▁via ▁capture , ▁while ▁the ▁g ase ous ▁nature ▁of ▁the ▁prim aries ▁also ▁make ▁formation ▁from ▁collision ▁de br is ▁unlikely . ▁The ▁outer ▁mo ons ▁of ▁the ▁giant ▁plan ets ▁tend ▁to ▁be ▁small ▁and ▁have ▁ecc ent ric ▁or bits ▁with ▁arbitrary ▁incl in ations . ▁These ▁are ▁the ▁characteristics ▁expected ▁of ▁captured ▁bodies . ▁Most ▁such ▁mo ons ▁orbit ▁in ▁the ▁direction ▁opposite ▁the ▁rotation ▁of ▁their ▁primary . ▁The ▁largest ▁irregular ▁moon ▁is ▁Ne pt une ' s ▁moon ▁T rit on , ▁which ▁is ▁thought ▁to ▁be ▁a ▁captured ▁K ui per ▁bel t ▁object . ▁ ▁Mo ons ▁of ▁solid ▁Sol ar ▁System ▁bodies ▁have ▁been ▁created ▁by ▁both ▁coll isions ▁and ▁capture . ▁Mars ' s ▁two ▁small ▁mo ons , ▁De imos ▁and ▁Ph ob os , ▁are ▁thought ▁to ▁be ▁captured ▁astero ids . ▁The ▁Earth ' s ▁Moon ▁is ▁thought