Hidden corridor in Egypt’s Great Pyramid mapped with cosmic rays

A previously hidden corridor hidden deep within the 4,500-year-old Great Pyramid of Giza in Egypt has been mapped in detail for the first time, and researchers have also peered inside with an endoscopic camera.

The corridor was first discovered in 2016, but the researchers didn’t want to damage the monument to gain access. The Pyramid is the only one of the Seven Wonders of the Ancient World that has survived, and for thousands of years it was the tallest man-made structure in the world at 146 meters high. It was built around 2560 BC. during the reign of Pharaoh Khufu.

Using a space muon radiography technique developed by scientists at Nagoya University in Japan, an international team of researchers was able to confirm that the corridor is 9 meters long and has a cross section of approximately 2 meters by 2 meters.

Cosmic ray muon x-ray traces the level of muons passing through the pyramid. These particles are a natural form of radiation resulting from cosmic rays and constantly bombard the Earth’s surface. In this method, the researchers use muon detectors placed at various points around the monument. Muons are partially absorbed by the stone from which the pyramids are built, which means that the method allows researchers to identify cavities inside the structure.

This approach has been used to map the interior structures of the pyramids since 1971, when it was first applied at Giza.

Using their accurate corridor map, the researchers identified a possibility. “We realized that it was so close to the surface that endoscopy was possible,” says Sebastian Procureur from the University of Paris-Saclay in France.

They inserted a small camera similar to those used in medical procedures to see the corridor for the first time in thousands of years.

“We knew there was a cavity, but of course when you see it, it’s completely different,” says Procureur. “We felt strange when we saw it.”

And yet the Prosecutor was glad for one thing. “This is a controversial opinion, but I am glad that the cavity was empty. I would not want to participate in the opening of the tomb.