NASA – These are the highest-resolution color images of any part of Saturn’s rings, to date, showing a portion of the inner-central part of the planet’s B Ring. The view is a mosaic of two images that show a region that lies between 61,300 and 65,600 miles (98,600 and 105,500 kilometers) from Saturn’s center.
This image is a natural color composite, created using images taken with red, green and blue spectral filters. The pale tan color is generally not perceptible with the naked eye in telescope views, especially given that Saturn has a similar hue.
The material responsible for bestowing this color on the rings — which are mostly water ice and would otherwise appear white — is a matter of intense debate among ring scientists that will hopefully be settled by new in-situ observations before the end of Cassini’s mission.
The different ringlets seen here are part of what is called the “irregular structure” of the B ring. Cassini radio occultations of the rings have shown that these features have extremely sharp boundaries on even smaller scales (radially, or along the direction outward from Saturn) than the camera can resolve here. Closer to Saturn, the irregular structures become fuzzier and more rounded, less opaque, and their color contrast diminishes.
The narrow ringlets in the middle of this scene are each about 25 miles (40 kilometers) wide, and the broader bands at right are about 200 to 300 miles (300 to 500 kilometers) across. It remains unclear exactly what causes the variable brightness of these ringlets and bands — the basic brightness of the ring particles themselves, shadowing on their surfaces, their absolute abundance, and how densely the particles are packed, may all play a role.
Image: NASA/JPL-Caltech/Space Science Institute