 Ceres is in a near @-@ 1 : 1 mean @-@ motion orbital resonance with Pallas ( their proper orbital periods differ by 0 @.@ 2 % ) . However , a true resonance between the two would be unlikely ; due to their small masses relative to their large <unk> , such relationships among asteroids are very rare . Nevertheless , Ceres is able to capture other asteroids into temporary 1 : 1 <unk> orbital relationships ( making them temporary <unk> ) for periods up to 2 million years or more ; fifty such objects have been identified . 
