The nucleus of Comet 9P/Tempel 1: Shape and geology from two flybys

► Tempel 1 has two types of terrain, rough pitted and smoother, flow-like materials. ► The smooth materials are collected in low regions. ► Changes observed between the Deep Impact and Stardust-NExT encounters involve scarp retreat. ► Timescales for formation of the surface's topography appear to be tens to perhaps hundreds of orbits.