Dec 28, 2016
Cassini Buzzes Pandora, Saturn's Moon of Chaos
As Cassini is now making some danger-close passes of the gas giant's rings ahead of its "Grand Finale", it's setting itself up for some pretty magnificent (and unprecedented) views of Saturn's moons and rings. During its third ring-grazing orbit, Cassini was able to image Pandora, one of Saturn's innermost moons, from a record-breaking distance of only 25,200 miles (40,500 kilometers), 6,800 miles (10,900 kilometers) closer than its previous closest approach in 2005. The spacecraft's narrow-angle camera captured this view on Dec. 18.
Pandora was discovered in 1980 after analysis of photos taken by the Voyager 1 probe during its grand tour of the solar system's planets. The moon measures only 52 miles (84 kilometers) across and is known to have at least two large craters around 19 miles (30 kilometers) wide. These large craters are filled with debris and a thick layer of dust covers its surface, smoothing over the smaller craters.
The moon orbits Saturn at an average distance of around 88,000 miles and zooms around the planet once every 15 hours.
This observation will be used to better understand how Pandora formed and what it's made of. Known to have a fairly low density and high albedo (reflectivity), scientists think the moon is likely porous and composed of water ice. According to NASA, Pandora has a chaotic orbit that is heavily influenced by orbital resonances with other moons, causing it to speed up and slow down during its path around Saturn. It is thought that Pandora's orbital weirdness may disrupt the grains of dust and debris in Saturn's thin F-ring, while "shepherd moon" Prometheus, which orbits just inside of the ring, works to keep the ring particles in check.
Read more at Discovery News