Precise characterization of a corridor-shaped structure in Khufu's Pyramid by observation of cosmic-ray muons.

Khufu's Pyramid is one of the largest archaeological monument all over the world, which still holds many mysteries. In 2016 and 2017, the ScanPyramids team reported on several discoveries of previously unknown voids by cosmic-ray muon radiography that is a non-destructive technique ideal for the investigation of large-scale structures. Among these discoveries, a corridor-shaped structure has been observed behind the so-called Chevron zone on the North face, with a length of at least 5 meters.

3D imaging of a nuclear reactor using muography measurements.

The inspection of very large or thick structures represents one of the biggest challenges for nondestructive techniques. For such objects, a particularly powerful technique is muography, which makes use of free, natural cosmic-ray muons. Among other applications, this technique has been applied to provide two-dimensional (2D) images of nuclear reactors, pyramids, or volcanos.

Discovery of a big void in Khufu's Pyramid by observation of cosmic-ray muons.

The Great Pyramid, or Khufu's Pyramid, was built on the Giza plateau in Egypt during the fourth dynasty by the pharaoh Khufu (Cheops), who reigned from 2509 bc to 2483 bc. Despite being one of the oldest and largest monuments on Earth, there is no consensus about how it was built. To understand its internal structure better, we imaged the pyramid using muons, which are by-products of cosmic rays that are only partially absorbed by stone.