Two years ago, a team of research scientists announced they would use muon tomography to explore the Great Pyramid of Giza, also known as the Pyramid of Khufu. They planned to image internal structures that are inaccessible to researchers, and hopefully shed some light on the techniques used in its construction. What they found was stranger than anyone expected. We now know that there’s a massive internal void inside the Great Pyramid at least 30m (100 feet) long–the first discovery of a new chamber or void in the Pyramid since the 19th century.
The research team used three different muon detection technologies and confirmed the results via three independent analysis teams before coming forward with their results. The initial muon tomography survey was carried out because we still don’t know how the pyramids were built. Documents that date from Khufu’s reign were discovered in 2013, but they only describe how the stones were transported to the construction site, not how the pyramid itself was constructed. The muon tomography scanning technology that found this enormous chamber can’t be used to detect small air shafts, and the density of the pyramid required an observation period of several months to acquire enough muons to accurately scan the pyramid’s internal structure at all.
The cross section and length of the void establish it as a major structure within the pyramid, with the same approximate muon data patterns as the Grand Gallery, shown below. This points to the space being a deliberate void (it may not be a chamber, as such) within the structure. Contrary to the way pyramids are often portrayed in media, they typically don’t feature vast labyrinths of corridors or enormous treasure chambers that fill the structure. As the image below shows, the majority of the Great Pyramid is solid rock:
Even with this void, most of the Pyramid of Khufu is solid stone. Image by ScanPyramids
Note that the solid stone construction of the Great Pyramid and the other surviving pyramids at Giza is actually uncommon. In later dynasties, the Egyptians used different construction techniques, including cores made from a rubble pile, low-quality limestone, and mud bricks. The Egyptians built pyramids for thousands of years, but the best preserved sites are typically the oldest, when the pyramids were set directly on bedrock and built from stone-block cores. Contrast the preservation of the Great Pyramid with the remaining structure of the Pyramid of Amenemhat I (Amenemhat I ruled from 1991-1962 BC, while the Great Pyramid of Khufu was constructed from 2580-2560 BC). Despite being roughly 600 years older, the Great Pyramid is in vastly better condition.
This is part of the reason it’s been so difficult to determine how the Egyptian pyramids were constructed. We have clear evidence that they were built differently in different eras, from vastly different materials.
It is not clear when or if researchers will be allowed to try to open the new void within the pyramid. After the widescale looting of its cultural artifacts in the 19th and 20th centuries, Egypt is now very careful about the types of explorations it allows. Researchers will have to devise a plan to explore the spaces with a minimum of damage to the structure–a task that would be made much easier if any small adjoining passages can be found linking the void to any other accessible part of the pyramid. Because the muon tomography scanning techniques only work for finding large spaces, there’s still a chance that some of these exist.
Feature image is of the Grand Gallery inside the Great Pyramid, located below the void this project discovered.