Radii, shapes, and topography of the satellites of Uranus from limb coordinates

Limb coordinates are used to find the radii, shapes, and local topography of the five large satellites of Uranus. The technique provides a direct measure of ellipsoidal shapes of satellites and fixes radii to subpixel accuracy. Umbriel, Titania, and Oberon are best fit by spheres. Miranda and Ariel are ellipsoids whose equatorial bulges are consistent with published mean densities. Limb topography on Miranda shows substantial deformation of both old cratered terrain and the younger coronae and complex faulting and uplift at the margins of the coronae. The maximum deformation is about 10 km. Umbriel's limb shows a basin of undetermined origin about 500 km across and 6 km deep.