Mars Reconnaissance Orbiter snapped this giant Martian sand dune that has a turquoise blue hue in enhanced color.
Sand dunes often accumulate in the floors of craters. In this region of Lyot Crater NASA's Mars Reconnaissance Orbiter (MRO) shows 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 surrounding.
What a sight to behold in person that would be!
• Once in a Blue Dune (NASA/JPL)