The extensive ribbonlike cloud structure in Saturn's atmosphere is visible in this Voyager 2 green-filter photograph, obtained Aug. 23 from a range of 2.5 million kilometers (1.6 million miles). Some Voyager scientists have interpreted the ribbon to be a large-scale atmospheric wave; it is believed to lie in a rapid eastward-moving jet stream. The presence of vortices adjacent to the ribbon itself will help scientists understand the relationship between such structures and the strong jet-streams present in Saturn's atmosphere. The smallest features visible in this photograph measure about 50 km. (30 mi.) across. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

[Caption update June 25, 2012]
This wavy jetstream is strong and persistent. As of 2012, it no longer resembles a ribbon but it still flows eastward at 42 degrees north latitude (see PIA14916 and PIA14917). Scientists using data from the Cassini spacecraft observed for the first time how eddies, or rotating storms, accelerate this and other jets at two different altitudes on Saturn.