When on the hunt for ancient civilizations, it's not all about Pyramids and monuments. Archaeologists have developed a method of spotting smaller human settlements using spy-satellite photos from the 60s, digital maps and modern multi-spectral images of the planet's surface. The Scientists are looking for "anthrosols" which are left by decayed organic matter and mud-brick buildings. Containing a higher levels of organic matter, anthrosols impart a different texture and appearance to untouched soil, giving it a distinct visual signature. Software is used to spot these visual fingerprints from images over a 50 year period. Data from NASA's Shuttle Radar Topography Mission is also used to determine the volume of the matter
