This radar image, obtained by Cassini's radar instrument on 22 February 2007, shows dunes surrounding a bright feature on Saturn's moon Titan.
Dunes have been previously seen on Titan, so far concentrated near the equator. They are thought to be composed of small hydrocarbon or water ice particles - probably about 250 microns in diameter, similar to sand grains on Earth. These are formed into dunes by the prevailing west-to-east surface winds, and are probably ‘longitudinal’ (lying in the same direction as the average wind) rather than transverse dunes, more common on Earth.
There are several kinds of interaction between the dunes and the brighter features in this image. At the left, the dunes seem to be covering the bright material, while at the centre and right, they seem to be terminated against it. At the lower centre and lower right, they flow around it.
This image was taken in synthetic aperture mode at 700-metre resolution, and is centred at about 3.5 °S latitude and 37.3 °W longitude (North is toward the left of the image).