July 16, 2001
Bands of eastward and westward winds on Jupiter appear as concentric rotating circles in a movie composed of Cassini images which have been reprojected to appear as if the viewer were floating over Jupiter's north pole. The sequence covers 70 days, from October 1 to December 9, 2000. Cassini's narrow-angle camera cap tured the images of Jupiter's atmosphere in near-infrared light.
What is surprising in this view is the coherent nature of the high latitude flows, despite the very chaotic, mottled and non-banded appearance of the planet's polar regions. This is the first extended movie sequence to show the coherence of the circumpolar winds and the features blown around the planet by them.
Jupiter's alternating eastward and westward jet streams flow in concentric rings around the pole, with equatorial motions visible in the corners. The large dark features flowing counterclockwise near the equator are "hot spots" where cloud cover is relatively thin.
Cassini collected images of Jupiter for months before and after its closest approach to the planet on December 30, 2000. Six images of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire spectral sequence was then repeated generally every second Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours. The images used for the movies shown here were only those taken 20 hours apart and through a filter centered at 751 nanometers. The six images covering each rotation were mosaicked together to form a cylindrical map extending from 75 degrees North to 75 degrees South in latitude (vertical direction) and covering 360 degrees in circumference.