The "Scars" of Tethys...

Caption NASA:"The Cassini spacecraft spies four large impact basins on the Southern Hemisphere of icy Tethys.
Tethys (approx. 1071 Km, or 665 miles across), like the other airless worlds of the Solar System, wears the record of countless impacts experienced over the eons.
Lit terrain seen here is on the leading hemisphere of Tethys. North is up and rotated 15° to the left.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 21, 2007. The view was obtained at a distance of approx. 452.000 Km (such as about 281.000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 54°.
Image scale is roughly 3 Km (about 2 miles) per pixel".