Once in a Blue Dune
Sand dunes often accumulate in the floors of craters. In this region of Lyot Crater there is a field of classic barchan dunes.
Just to the south of the group of barchan dunes is one large dune with a more complex structure. This particular dune, appearing like turquoise blue in enhanced color, is made of finer material and/or has a different composition than the surroundings.