Illustration of Mercury showing a new model of crustal thickness with cutaway showing a model of the planet’s interior structure. Crustal thickness is shown in shades of red and white indicating thick crust and shades of blue indicating thin crust. Mercury’s interior is dominated by its inner solid core and outer liquid core. Downward mantle flow in Mercury’s mantle results in thickening of the crust and also generates contraction (upmost black arrows in the inset diagram) within the thickening crust. It is the contraction that influences the localization of the thrust fault scarps. (Smithsonian Institution)