Dione

Dione is Saturn's fourth large moon, and orbits 235,000 miles (378,000 km) from Saturn with an orbital period of 2.74 days.

Dione was discovered in 1684 by Giovanni Cassini, and in spite of its smaller diameter of 683 miles (1120 km), it can also be seen in small telescopes. The Voyager spacecraft discovered bright wispy streaks on its surface that overlay a darker, cratered background, indicating that they are newer. But recent photos from the Cassini orbiter have shown that these are ice cliffs created by tectonic fractures, some several hundred meters high.