NASA’s Cassini probe obtained new images of Saturn’s moon Dione during a close flyby on June 16, 2015.
This image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 16, 2015. The bright rings of Saturn can be seen at left. North on Dione is up and rotated 44 degrees to the left. Image credit: NASA / JPL-Caltech / Space Science Institute.
Dione is the fourth nearest of the major regular moons of Saturn. It was discovered in 1684 by the Italian-born French astronomer Giovanni Cassini and named after the Titaness Dione of Greek mythology.
Dione has a density of 1.43 grams per cm3, which is higher than the other moons of Saturn except for Titan. Planetary scientists have suggested that the moon is probably composed of a rocky core making up one-third of its mass, with the rest water-ice.
At 698 miles (1,123 km) in diameter, Dione is the 15th largest moon in the Solar System.
It orbits Saturn every 2.7 Earth days at a distance of 234,000 miles (377,400 km), which is roughly the same distance that the Moon orbits around our planet.
Dione has probably been tidally locked in its current position for the past several billion years. This is reflected in the average surface albedo of the leading and trailing hemispheres.
This image of Dione was taken with the wide-angle camera aboard Cassini on June 16, 2015. Also making an appearance in this image is Saturn’s moon Enceladus, seen in the upper right, just above the bright line of Saturn’s rings. Image credit: NASA / JPL-Caltech / Space Science Institute.
Dione’s features include heavily cratered terrain, moderately cratered plains, lightly cratered plains, and whispy material. The heavily cratered terrain has huge craters, more than 60 miles (100 km) in diameter. The plains area tends to have craters less than 20 miles (30 km) in diameter.
The cratered surface of Dione is revealed in the new images from NASA’s Cassini spacecraft.
Cassini buzzed past the icy moon on June 16, 2015. This was Cassini’s fourth targeted flyby of Dione and the space probe had a close approach altitude of 321 miles (516 km) from its surface.
On August 17, 2015 Cassini will make its final flyby of Dione, diving to within 295 miles (474 km) of the surface.
