Slipping into shadow, the South polar vortex at Saturn’s moon Titan still stands out against the orange and blue haze layers of its atmosphere. Images like this, from the international Cassini spacecraft, lead scientists to conclude that the polar vortex clouds form at much higher altitudes – where sunlight can still reach – than the lower surrounding haze. This image was taken in July 2013. See http://photojournal.jpl.nasa.gov/catalog/PIA17177
