Saturn's moon Dione, as captured by Cassini

This dramatic crescent image was actually taken as the Cassini spacecraft was heading away from Dione at least 37,000 miles (59,000 kilometers) from the Saturn satellite. To get a sense of Dione, it is slightly less than a third the size of our own moon, and orbits Saturn at about the same distance (234,000 miles/377,000 km). All image credits: NASA/JPL-Caltech/Space Science Institute

Dione is captured as the Cassini space probe flies toward the moon at a distance of about 98,000 miles (158,000 kilometers). Visible are the rings of Saturn. Dione itself is quite icy but has a thin atmosphere, a discovery made in 2011. Sven Simon at the University of Cologne in Germany. "Dione's atmosphere is strong enough to disturb [Saturn's] magnetic field," Simon told National Geographic.

Captured during Cassini's final close flyby, Dione is seen hanging in front of Saturn from about 45,000 miles (73,000 kilometers) away. Mission scientist Dr Carolyn Porco said it would be a long time before there is another glimpse of this far-off world . “Right down to the last, Cassini has faithfully delivered another extraordinary set of riches. How lucky we have been,” she said.

Captured during an earlier flyby on April 11, 2015, from about 68,000 miles (110,000 kilometers) away. Dione's linear features, known as chasmata, stand in stark contrast to the pockmarked craters often found on lunar surfaces. Dione is packed with icy cliffs, though it's still not completely understood how these patterns were formed.

This view of Dione was captured just as Cassini was nearing its final close approach at 39,000 miles (70,000 kilometers) away. With this level of resolution it's possible to clearly see Evander, a 220-mile wide basin on the lower right of the moon's surface; by far, the moon's largest crater.

Dione's rolling, cratered landscape shows probable impacts from meteorites, large and small, as well as possible evidence of volcanic activity. Cassini's altitude from the surface was as close as 470 miles (750 kilometers) when gathering these images. To get an idea of resolution, each digital pixel represents about 150 feet (45 meters) across the lunar surface.

As the Cassini spacecraft flew about 365 miles (588 kilometers) over the surface it managed to capture some of the highest resolution of Dione's surface by the mission to date. This image captures the region near the day-night boundary, with indirect sunlight reflecting off Saturn. This image was from the spacecraft's closest approach to the icy moon.