How NASA satellites unearthed Egypt’s lost pyramids

In a recent satellite survey of Egypt, archaeologists have reported the unexpected discovery of as many as 17 lost pyramids.

Also among the findings were more than 1,000 tombs and 3,000 ancient settlements. Ground level excavations have already confirmed the existence of two of the pyramids. These details were released in advance of “Egypt’s Lost Cities,” a documentary produced by the BBC that chronicles the research and is scheduled to air on Monday.

The research team, led by University of Alabama’s Sarah Parcak, made the discovery after analyzing NASA satellite images taken from 435 miles above the earth. Ancient Egyptian buildings were comprised of mud brick that are denser than the soil surrounding them, allowing scientists to make out the shapes of houses, temples and tombs. While the cameras used were powerful enough to scan the earth’s surface and locate objects less than a meter in diameter, many of these structures — buried thousands of years ago — were also uncovered using infrared imaging technology.

Many of us have become familiarized with infrared from medical scans that show various levels of heat emanating from human bodies. But some people may be surprised to learn that the same principle can also be used to reveal objects hidden beneath the earth’s surface. This is because the sun and the earth’s hot core generates geothermal radiation that moves outward, causing objects beneath the sand to give off their own signature level of infrared light. These signatures can be measured by special instruments and used to identify ancient relics.

Parcak, an Egyptologist, suspects that there are even more structures left to be discovered — including artifacts that belong to entire a lost city — and that sophisticated space technology will likely be the way forward in the field of archaeology.

“These are just the sites [close to] the surface. There are many thousands of additional sites that the Nile has covered over with silt. This is just the beginning of this kind of work,” Parcak told the BBC. “Indiana Jones is old school, we’ve moved on from Indy. Sorry, Harrison Ford.”