In this Landsat 7 image from 2003, the amber and caramel lattices seen are large, linear sand dunes in the Erg Chech dune sea located in the Sahara region of western Algeria. An erg, meaning dune field in Arabic, is a wide, flat area of desert covered with windblown sand and little vegetation cover. The dunes are formed when large amounts of transported sand are halted by topographic barriers. The largest dunes can take up to a million years to build. Ergs are also found on other celestial bodies such as Venus, Mars, and Saturn’s moon Titan.