Saturn casts a deep shadow across its own rings in this unique view taken as Voyager 1 looked back after passing the planet in November 1980.
As part of its in-depth exploration of Saturn, Voyager 1's instruments recorded that the upper atmosphere is made up of about 7 percent helium, while the rest is hydrogen. Both Voyagers measured winds near Saturn's equator blowing at about 1,100 miles (1,770 kilometers) an hour.
The probes also discovered six new celestial bodies around Saturn, bringing its known total at the time to 17 orbiters. Since then, astronomers using various instruments have cataloged more than 45 natural satellites orbiting Saturn.