SHARAD radar cross-section
On the left is a normal SHARAD radar cross-section of the north polar cap of Mars. The right side shows a continuation of that cross-section, with colors that correspond to different wavelengths of the radar signal. The changing color patterns reveal new details of the thickness and spacing of dust layers within the ice. The total width of the image is 440 km, and the ice cap here is about 1.5 km thick. (Smithsonian Institution/Planetary Science Institute).