Titan’s South Polar Vortex in Motion
Cassini captures a south polar vortex, or a mass of swirling gas around the pole in the atmosphere, at Saturn’s moon Titan.
The swirling mass appears to execute one full rotation in about nine hours - much faster than the moon’s 16-day rotation period. The images were taken before and after a distant flyby of Titan on June 27, 2012.
Since Cassini arrived in the Saturn system in 2004, Titan has had a visible “hood” high above the north pole. It was northern winter at Cassini’s arrival, and much of the high northern latitudes were in darkness. But the hood, an area of denser, high altitude haze compared to the rest of the moon’s atmosphere, was high enough to still be illuminated by sunlight.
The seasons have been changing since Saturn’s August 2009 equinox signaled the beginning of spring in the northern hemisphere and fall in the southern hemisphere for the planet and its many moons. Now the high southern latitudes are moving into darkness. The formation of the vortex at Titan’s south pole may be related to the coming southern winter and the start of what will be a south polar hood
Image Credit: NASA/JPL-Caltech/Space Science Institute