Asteroids Bennu and Ryugu

Both the 525-m diameter Bennu asteroid visited by NASA’s OSIRIS-REx and 1-km diameter Ryugu asteroid reached by Japan’s Hayabusa2 possess the same distinct spinning-top shape and similar material densities. However the pair contain differing amounts of water, as revealed in spectral mapping of hydrated materials. Ryugu appears weakly hydrated compared to Bennu, despite being a comparative youth in asteroid terms, estimated at a mere 100 million years old.