November 30, 2009
This image shows the northern and southern hemispheres of Titan, showing the 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.
Credit: The mosaic includes Cassini SAR, ISS, and VIS images (NASA/JPL/Caltech/University of Arizona/Cassini Imaging Team).