Fission and reconfiguration of bilobate comets as revealed by 67P/Churyumov–Gerasimenko

A modelling study of the bilobate nucleus of comet 67P/Churyumov–Gerasimenko reveals that it has spun much faster in the past, but that its chaotically changing spin rate has so far prevented it from splitting; eventually the two lobes will separate, but they will be unable to escape each other and will ultimately merge again—a situation that seems to be common among cometary nuclei.