 Ceres was once thought to be a member of an asteroid family . The asteroids of this family share similar proper orbital elements , which may indicate a common origin through an asteroid collision some time in the past . Ceres was later found to have spectral properties different from other members of the family , which is now called the Gefion family after the next @-@ lowest @-@ numbered family member , <unk> Gefion . Ceres appears to be merely an <unk> in the Gefion family , <unk> having similar orbital elements but not a common origin . 
