Selam

The Lucy spacecraft's flyby of asteroid 152830 Dinkinesh unveiled its moon, Selam, about 220 meters (720 feet) in diameter, forming a binary asteroid system. Selam, named after an Australopithecus afarensis fossil, is the first known contact binary satellite associated with an asteroid. Its formation likely resulted from rotational fissioning caused by the YORP effect, where an asteroid's rapid rotation ejects material into orbit, eventually forming a satellite. The YORP effect might have also contributed to the fissioning of Selam itself. Another scenario is Selam arose potentially from a collision within a triple asteroid system, highlighting the intricate dynamics and potential instability of multiple asteroid systems, offering valuable insights into their formation and evolution within the solar system.