It has been discovered that Titan, the largest moon orbiting the planet Saturn, has sand dunes.  Radar images display 100-kilometre-long dark strips similar to those found in Africa and Saudi Arabia.  The Titan also has winds, not formed by the Sun, but by the strong gravitational pull of Saturn. These winds blow the sand into piles and causes erosion to break rocks into sand. Studies have shown that the size of the average sand grain is roughly three times bigger than that found on Earth and scientists are still not clear as to what constitutes the sand on Titan. They do know that it is not made of silica since there are no rock particles exposed on the moon. Similar to how rock is eroded by water on Earth there have been glimpses of channels carved into the ice surface, presumably by liquid methane.

Source: Spider