Getting into the groove of Saturn’s rings

Image: NASA/JPL-Caltech/Space Science Institute.
Image: NASA/JPL-Caltech/Space Science Institute.

From afar, Saturn’s rings look like a solid, homogenous disc of material. But upon closer examination in this image from the Cassini probe orbiting the planet, we see that there are varied structures in the rings at almost every scale imaginable.

Structures in the rings can be caused by many things, but often times Saturn’s many moons are the culprits. The dark gaps near the left edge of the A ring (the broad, outermost ring here) are caused by the moons (Pan and Daphnis) embedded in the gaps, while the wider Cassini division (dark area between the B ring and A ring here) is created by a resonance with the medium-sized moon Mimas (which orbits well outside the rings). Prometheus is seen orbiting just outside the A ring in the lower left quadrant of this image; the F ring can be faintly seen to the left of Prometheus.

This view looks toward the sunlit side of the rings from about 15 degrees above the ringplane. The image was taken in red light with the Cassini spacecraft wide-angle camera on 8 January 2015.

The view was obtained at a distance of approximately 911,000 kilometres (566,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 37 degrees. Image scale is 54 kilometres (34 miles) per pixel.