Lost Cities of the Amazon Discovered From the Air

From an aircraft, a lidar system fires down a grid of infrared beams, hundreds of thousands per second, and when each beam strikes something on the Earth’s surface it bounces back with a measure of distance. This produces an enormous cloud of data points, which can be fed into computer software that creates high resolution images in which scientists can digitally deforest the Amazon. By scrubbing away trees the maps reveal the Earth’s surface and the archaeological features on it. In this case, the images clearly showed 26 unique sites, including 11 that were previously unknown.