1960s aerial spy photos reveal hidden archaeological sites

Archaeologists use satellite photos to spot potential archaeological sites, but urban sprawl and other human development has erased many traces of ancient civilizations. To get around that, Harvard's Jason Urs and Emily Hammer from the University of Pennsylvania figured out how to effectively go back in time to when the land was less despoiled. They dug up and archived a trove of U-2 spy photos from the '50s and '60s, eventually finding ancient canals and "desert kite" stone structures built in northern Iraq by the Assyrians up to 8,000 years ago.

The high resolution photos taken by U-2 spy planes were declassified in 1997, but had never been scanned or indexed, making it hard for archaeologists to tell what they were looking at. Ur and Hammer, experts in Middle East archaeology, saw the potential of the photos after meeting a Chinese colleague who who managed to dig up U-2 images of his home town.

They found the rolls of film in a Kansas National Archives facility and photographed the negatives using a 100mm macro lens. Then, they stitched them together using GIS (geographic information systems) software in order to create a GPS-like map of the region as it was 60 years ago. Since the U-2 spy planes flew at around 70,000 feet, they produced much more detailed images than the highest-resolution Corona satellites of the day (below).

As you turn the spool of a film roll following the path of the U2 plane, you may not know exactly what you'll see in unfamiliar places, so there's often a sense of exploration and discovery," Hammer said in a statement. "Other times, the pilots were flying over regions I knew by heart from travel and study, and I would almost hold my breath, hoping that the plane had veered just a little to the right or left."