Dione and Rhea, two of the many satellites circling Saturn, pass each other like two ships in the night.

The Cassini spacecraft took this raw image on Oct. 11 from about 438,622 miles (705,894 kilometers) away from Dione during a recent flyby.

Dione appears in the foreground and was about 205,000 miles (330,000 kilometers) away from Rhea as it eclipsed its fellow moon from Cassini’s perspective. For comparison, the Earth and Moon are typically separated by a distance of about 239,227 miles (385,000 kilometers), according to NASA.

With a diameter of about 695 miles (1,118 kilometers) and rocky core covered in water ice, Dione is Saturn’s second densest moon after Titan. The moon orbits Saturn at a distance about 234,500 miles (377,400 kilometers) from its parent planet.

Rhea, on the other hand, has a relatively low density and a diameter of about 949 miles (1,528 kilometers). Rhea does contain a rocky core surrounded by water ice, but has a wider orbit. Rhea circles its ringed parent from a distance of about 327,487 miles (527,040 kilometers) away.

While its Dione flyby is over, Cassini will return to Rhea. The probe is slated to make its next flyby based Rhea on Nov. 26, 2005, then swing past once more on Aug. 30 2007.

-- SPACE.com Staff

Credit: NASA/JPL/Space Science Institute.