Global pattern of Titan's dunes: Radar survey from the Cassini prime mission

Abstract

We present a map of the orientation and extent of Titan's sand dunes derived from the complete radar imaging dataset from the Cassini prime mission. The 16,000 dune segments we have mapped cover ~8% of the Titan's surface (suggesting a total coverage of ~20%), are confined within 30° of the equator, and show local and regional deviations of dune orientation of up to about 40° from due Eastwards. There is no obvious global longitudinal pattern, although some divergence with latitude is apparent. The most striking pattern is one of collimation by and divergence around bright and/or high terrain. Obstacles 100-300 m high obstruct dunes when the local slope is 1/50 or steeper, while slopes 1/200 or shallower cause dunes to thin out as they climb, or to deviate around the obstacles.