Scientists have found a way to use thermal remote sensing to detect hidden bedrock under a thin layer of soil in desert areas like the southwestern United States. By studying heat flow in the soil, they discovered that changes in the thickness of the soil layer can affect surface temperature. This means that thermal imaging can reveal buried features like faults and river channels on rocky surfaces. By analyzing temperature differences as small as 0.1 degrees Celsius, they can even spot linear topographic features hidden under several meters of soil. This technique could help uncover important geological features that are normally hidden from view.