TUCSON, Arizona, March 17 -- The University of Arizona posted the following news release: * * * Asteroid Bennu's rugged surface baffled NASA. We finally know why * In one of the biggest surprises of NASA's OSIRIS-REx mission, its target asteroid, Bennu, turned out to be a jagged, rugged world covered in large boulders, with few of the smooth patches that earlier observations from Earth-based instruments had indicated. "When OSIRIS-REx got to Bennu in 2018, we were surprised by what we saw,  more