The swirling atmospheres and other dynamic features of the outer planets are now studied by combining individual images taken at intervals into continuous movies. The images shown here represent many hours of Earth-based and spacecraft observations that are used to measure magnetic field variations and wind speeds in the atmospheres of Jupiter and Saturn.
Io Sodium Cloud
This image of Io's neutral sodium cloud was recorded on May 5, 1981, at the NASA/Jet Propulsion Laboratory's Table Mountain Observatory. The size and location of Io are indicated by the orange dot within the crossbars. Earth-based telescopic imaging of the cloud since 1976 has shown that it changes its shape in response to variations in the magnetic field of Jupiter, and is composed of sodium atoms originating from Io. More about Io.
Atmospheric Rotation of Jupiter
Multiple images collected by the Cassini spacecraft in October and November 2000 are combined to make this animation of the motion of Jupiter's atmosphere. Storm systems form where jetstreams of eastward and westward moving clouds pass each other. The Great Red Spot rotates counterclockwise once every six days. More information on the atmosphere of Jupiter.
High resolution images from Voyager 2 show Saturn's rings and their spoke-like features. The origin of the spokes is unknown, but analysis of Voyager data suggests that they are thin clouds of fine particles suspended above the rings by electrostatic forces. More information on Saturn's rings.
Atmospheric Rotation of Saturn
Like Jupiter, jetstreams in Saturn's atmosphere move in both westerly and easterly directions, and create storms where they pass each other. This animation of the motion of Saturn's atmosphere was made from images collected by the Cassini spacecraft in 2004. More information on the atmosphere of Saturn.