Saturn Images

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay

This is about as clearly as Saturn was ever seen from Earth in the days before space travel.

Pioneer 11, 1979

Most people are not aware that the first mission to Saturn was not Voyager but Pioneer 11 in 1979. Its images are horse-and buggy technology compared with Voyager, but even so, clearly superior to the best views from Earth, and they provided a lot of useful advance information for planning the Voyager missions. The rings are dark in this image because we are actually viewing the shaded side of the rings.
A detail of the rings taken by Pioneer 11. One of Saturn's satellites is also visible. Pioneer 11 almost discovered another satellite the hard way. From its effect on Saturn's magnetic field, Pioneer 11 apparently missed an undiscovered satellite by only a few hundred kilometers. The wide dark band in the rings is dark because sunlight cannot penetrate it; from the sunlit side it is the widest and brightest of the rings.

Some of the hot-dogger types at JPL thought it would be cool to fly Pioneer 11 through the gap in Saturn's rings, the Cassini Division. Cooler heads prevailed, pointing out that there could be a lot of fine unseen material orbiting in the gap. They were right. The bright band between two darker rings above is the Cassini Division, which shows up brightly from sunlight scattered off fine dust in the gap. Had we tried to steer through the gap, Pioneer would have been sandblasted to bits. It would have been a spectacular end to the mission, but that's not what spacecraft are for.


Saturn with rings (note the shadow of Saturn on the rings) and several of its satellites.
Close up of the structure of the rings. False colors added.
A truly awesome amount of garbage has been written about this picture. Some people think the outer rings pass in front of Saturn while the inner ring goes behind. Others think it's a mosaic of several pictures. In reality it's a single picture with the contrast cranked to maximum to show detail in the rings. Where the thin inner ring is viewed against the backdrop of space, it shows up. Against the bright disk of Saturn it becomes nearly invisible. A very similar situation occurs when cigarette smoke (similar in particle size) is invisible in a brightly lit room but becomes visible against a dark doorway.
Probably the most beautiful planetary image ever taken. A view that space artists like Chesley Bonestell saw only in their imaginations, a crescent Saturn. Planets can be seen as crescents only when they are between the viewer and the Sun; Voyager was looking back toward Saturn from beyond when it took this picture.

Return to Planetary Images Index
Access Course Notes on Planetary Geology
Access Astronomy Notes Index
Return to Professor Dutch's Home Page

Created 6 April 1999, Last Update 14 September 2018