Voyager 2 Images of Saturn's Ring System
(August 1981)

The Cassini Division and the A Ring

Saturn's outer A Ring in false color, constructed from Voyager 2 green, violet, and ultraviolet frames. The Cassini Division (lower right) is distinctly less red than the A Ring. Also visible, as a sequence of dark features in the outermost A Ring, is a series of orbital resonances with Saturn's inner moons. The 325 km wide Encke Division (upper left center) contains the tiny moon Pan. However, the cause of the narrower Keeler Gap (closer to the outer edge of the A Ring) and the gaps in the Cassini Division is not known.

The B and C Rings in False Color

The outer part of Saturn's C Ring (blue) and the inner part of the B Ring (yellow) are shown here in false color. The color difference blurs over the boundary between the rings. The Maxwell Gap and its eccentric ringlet, which appears yellow due to image mis-alignment, are in the left center of this frame.

Chemistry of the Rings

This highly enhanced false color view of Saturn's rings was assembled from clear, orange and ultraviolet images. Possible variations in chemical composition from one part of Saturn's ring system to another are visible as subtle color variations. In addition to the previously known blue color of the C Ring and the Cassini Division, the picture shows additional color differences (red-green) within and between the A and B Rings. The distance to Saturn was 8.9 million kilometers (5.5 million miles).

Spokes in the B Ring

Voyager 2 image FDS 43643.34 shows a distinct pattern of "spokes" in the B Ring, which is the broad, bright, middle ring of Saturn's three main rings. The spokes are made of dust that has been raised off of the ring particles, but the reason the spokes appear is unknown.

The Birth of a Spoke

Contrast enhancement reveals numerous spokes in the B Ring. In a sequence of four Voyager 2 images (shown here as inset panels), a small spoke is seen to appear in between several more prominent spokes. The arrow in the fourth inset image points to the new spoke.

Spokes in Forward-Scattered Light

After passing Saturn, Voyager 2 viewed the B Ring in forward-scattered light. The spokes, seen previously as dark streaks, are now seen as bright streaks from this phase angle. This indicates that the spokes are caused by tiny dust grains, comparable in size to the wavelength of light.

Structure in the B Ring

The B Ring is made up of narrow ringlets down to the limit of the image resolution. Some darker spokes are also visible. The Cassini Division is visible at upper right, and the A Ring is outside it; the C Ring is visible at lower right. This Voyager 2 image FDS 43904.47.

The B and C Rings

A closeup of the transition from the faint inner C Ring to the much brighter B Ring. Both rings show fine structure at many scales. This is Voyager 2 image FDS 43935.31.

Closeup of the B Ring

This is one of Voyager 2's closest looks at the B Ring, from August 25, 1981 at a distance of 743,000 km. The contrast has been enhanced to show the fine structure. The portion of the ring shown here is 6000 km wide and features as narrow as 10 km are visible.

Closeup of the Cassini Division

The Cassini Division, separating Saturn's A and B Rings, is maintained by the 2:1 resonance with Mimas. It was once thought to be empty, but this closeup view, Voyager 2 image FDS 43989.46, shows that it really contains several broad belts of material separated by empty "rifts".

The Discovery of Pan

The 10-km moon Pan shepherds open the 325 km wide Encke Gap in the outer part of Saturn's A Ring. This is the Voyager image in which is was discovered, FDS 43918.04. The region inside the green box is enlarged and enhanced as an inset at upper right to show Pan more clearly.

F Ring and Shepherds

Two tiny moons, Pandora and Prometheus, are seen here shepherding the F Ring. Prometheus, the inner shepherd, orbits faster and had just overtaken Pandora before this image was taken.

F Ring and Prometheus

This image shows Prometheus next to the F Ring. Prometheus is one of the shepherd moons associated with the F Ring. This image was taken on August 25, 1981 from a distance of 365,000 km. Note that the moon is distinctly elongated.

Crossing the Ring Plane

Image FDS 44006.49 shows the F Ring ansa just before Voyager 2 passed through the ring plane on August 26, 1981. The F Ring seems to be made up of a number of separate strands. In addition, the whole region inside the F Ring is not black, indicating that it is filled with fine dust.

The Foreshortened Rings

The last image taken by Voyager 2 just before it crossed Saturn's ring plane on August 26, 1981. The entire ring system is shown, but it is very nearly edge-on and highly foreshortened. The F Ring shows up prominently in the foreground.

Dark Side of the Rings

This color-enhanced Voyager 2 image shows the unlit side of the rings. Since the broad B Ring is very optically thick, very little light gets through so it appears very dark here. The A and C Rings let more light through so they appear brighter. The unlit side of the rings is rarely visible from Earth, except during the period of ring plane crossings such as occurred in 1995.

Last updated Apr-16-2007