Numerical simulations suggest asteroids (101955) Bennu and (162173) Ryugu are likely second or later generation rubble piles. - Walsh KJ; Ballouz RL; Bottke WF; Avdellidou C; Connolly HC Jr; Delbo M; DellaGiustina DN; Jawin ER; McCoy T; Michel P; Morota T; Nolan MC; et al. (Nature communications, 2024)