Observations of Saturnʹs Ribbon Wave 14 Years after Its Discovery

A singular feature in planetary atmospheres, the saturnian midnorthern latitude “ribbon” wave, was discovered in images obtained during the Voyager 1 and 2 encounters with the planet in 1980 and 1981. Here we present evidence of its first detection 14 years later (about half a Saturn year later) using archived Hubble Space Telescope images. The properties of the recovered wave (latitude location, dominant wavenumber, meridional amplitude, and reflectivity contrast) in 1994–1995 are similar to those observed during the Voyager era.