Dione and Tethys

Caption NASA originale:"Cassini offers this lovely comparison between two of Saturn's satellites, Dione and Tethys, which are similar in size but have very different surfaces.
Extensive systems of bright fractures carve the surface of Dione. The double-pronged feature Carthage Linea points toward the crater Turnus at the nine o'clock position near the terminator and Palatine Linea runs toward the moon's bottom limb near the five o'clock position.
In contrast, the surface of Tethys appears brighter and more heavily cratered. The large crater Penelope is near the eastern limb. The huge rift zone Ithaca Chasma, which is 3 to 5 Km deep and extends for about 2.000 Km from north to south across Tethys, is hidden in shadow just beyond the terminator. For comparison, the Grand Canyon in Arizona is about 1,5 Km deep and about 450 Km long.
The image was taken in visible light from a distance of approx. 1,5 MKM from Tethys and 1,6 MKM from Dione. The image scale is 9 Km/pixel on Tethys and 10 Km/pixel on Dione".