Williams and his colleagues started with radar imagery, where Cassini sent radio waves through the clouds to bounce off Titan’s surface in order to generate a map. This method covered slightly less than half of Titan’s surface in swooping, crossing tracts, but featured fine resolution the team could use to identify the moon’s different types of terrains, such as plains or dunes. They then overlaid that radar data with data from other cameras imaging visible and infrared light that were fuzzier, but covered the whole world, to learn how each landform appeared to each of Cassini’s various eyes. Finally, they used that global data from the other instruments to infer what types of land lay between the swaths of radar. “This particular map was focused on showing the variety of surface materials on a global scale,” Williams says.