The northern and southern hemispheres of Titan showing the great disparity between the abundance of lakes in the north and their paucity in the south. The hypothesis presented favors long-term flux of volatile hydrocarbons, predominantly methane, from hemisphere to hemisphere. Recently, the direction of transport has been from south to north, but the effect would have reversed tens of thousands of years ago.
NASA/JPL/Caltech/Univ. of Arizona/Cassini Imaging Team