Bennu’s active surface
The OSIRIS REx spacecraft’s observations of the rubble-pile asteroid Bennu reveal a weak and active surface undergoing rapid evolution. Bennu’s rugged geology — as imaged by the MapCam instrument onboard the spacecraft on 16 December 2018 — shows a surface littered with boulders, which cast long shadows owing to the high phase angle. Near the horizon, two large bowl-shaped craters can be seen: Ohnivak (~40 m diameter) and Alicanto (~60 m diameter).
see Bierhaus et al. , Perry et al. , Delbo et al. and News & Views by Arakawa