Sculpted polar dunes

A sea of dark dunes, sculpted by the wind into long lines, surrounds the northern polar cap covering an area as big as Texas in this false-color image taken in 2004 and 2004 by the Thermal Emission Imaging System instrument on NASA's Mars Odyssey orbiter. Areas with cooler temperatures are recorded in bluer tints, while warmer features are depicted in yellows and oranges.