Light and Dark: the Two Faces of Dione

Saturn’s moon Dione (pronounced DEE-oh-nee) is a heavily-cratered, 700-mile-wide world of ice and rock, its surface slashed by signature “wispy lines” that mark the bright faces of sheer ice cliffs. But Dione has some strange colorations too, evident here in a global map created in 2014 from Cassini images. Its leading half—the side that faces “forward” as…

Rhea Eclipses Dione While Cassini Watches

It’s been a while since I last made one of these: it’s an animation comprising 27 images acquired by Cassini in various color channels on October 11, 2015. It shows Saturn’s second-largest moon Rhea passing in front of the smaller and more distant* Dione, both partially illuminated by sunlight. I cleaned up some image artifacts…

Cassini Bids Farewell to Dione with Some Fantastic Final Views

NASA’s venerable Cassini spacecraft may still have another two years left in its exploration of the Saturn system but on Monday, August 17, it had its final intimate visit with Dione, one of Saturn’s largest natural satellites at nearly 700 miles (1,126 km) across. On that day Cassini passed within 300 miles (480 km) of Dione at 2:33 p.m. EDT (18:33…

A Colorful Christmas Moon

Merry Christmas and happy holidays everyone! Here’s your present from Lights in the Dark: a color-composite of Saturn’s moon Dione, lovingly made from raw images captured by the Cassini spacecraft on December 23. 700 miles (1120 km) wide, Dione (pronounced DEE-oh-nee) is covered pole-to-pole in craters and is crisscrossed by deep chasms and long, bright…

Dione in Color

Although made mostly of ice and rock, Saturn’s moon Dione (pronounced DEE-oh-nee) does have some color to it — although mostly chilly hues of steel blue, as seen in this color-composite made from raw images acquired by Cassini on July 23.

A Little Pas de Deux: Tethys and Dione

Saturn’s moon Tethys, its giant Odysseus crater in plain view, passes in front of of the slightly darker Dione in this animation made from several raw images acquired by Cassini earlier this month. Pretty cool!

Moons of Three

Saturn’s moons Dione and Titan lined up with the planet’s rings, seen here nearly edge-on, from the point of view of the Cassini spacecraft’s camera on September 17, 2011. This is a composite of three raw images taken with Cassini’s red, green and blue visible-light clear filters. Dione, 700 miles wide, is dwarfed by the…

A Fistful of Moons

This image from Cassini shows no less than five of Saturn’s moons in the same frame: Rhea (1,528 kilometers, or 949 miles across) is largest in the foreground; Dione (1,123 kilometers, or 698 miles across) can be seen just above the rings below Rhea near the center; Prometheus (86 kilometers, or 53 miles across) is just barely…

Ride Along With Rhea

Assembled from 29 raw images taken by the Cassini orbiter on Monday, April 25, this animation brings us along an orbital ride with Rhea as it crosses Saturn’s nighttime face, the planet’s shadow cast across the ringplane. Sister moons Dione and Tethys travel the opposite lane in the background, eventually appearing to sink into Saturn’s…

Prime PDS Picks

Every six to nine months or so the Cassini Imaging Center dumps orbiter image data into NASA’s Planetary Data System, or PDS. This data is accessible to anyone with an internet connection, but it can be a little awkward to find exactly what you’re looking for (unless you’re familiar with the technical nomenclature of the…

Dione in the Distance

Cassini looks past the southern pole of Rhea to get a view of Dione on the far side of the rings in this image, captured on January 11, 2011. Rhea, Saturn’s second-largest moon, is approximately 950 miles in diameter and is literally covered in craters. Dione, also heavily cratered, is nearly 700 miles wide. It’s…