Filippo Biondi’s Second Sphinx: What the Radar Images Show and Don’t Show

In summer 2026, news spread worldwide: beneath the Giza plateau lies a second Sphinx, roughly the size of the well-known one, previously undiscovered, revealed by satellite radar.

The claim comes from two Italian researchers, radar specialist Filippo Biondi and his co-author Corrado Malanga. It was presented in June 2026 at a public presentation, not in a peer-reviewed journal. This is already the third announcement from this research group regarding the same site.

Six weeks later, something happened that changed the situation. On August 10, 2026, the academic journal in which the underlying methodology had been published in 2022 withdrew that work. The editors cited serious methodological flaws and statistical errors that undermined the conclusions. The authors contest this decision.

Thus, the claim stands not only without its own publication but also without the foundational work it relied upon for its methodology.

A note on fairness is appropriate here. The following does not intend to impute bad faith. Both authors are recognized experts in radar analysis, and the question of whether unknown structures lie beneath a site inhabited for millennia is entirely legitimate. The assessment rests solely on whether the evidence provided holds up. This can be checked without speculating about intentions.

This page contextualizes the issue without dismissing the question prematurely. Whether anything lies under the sand of Giza is a serious question. Whether this procedure can answer it is another.

What Satellite Radar Can Actually Do

To contextualize this, one must understand what the method actually does.

Satellite radar scans the Earth's surface with microwaves. An image is created from the satellite's movement and the travel time of the reflected signals. The method is established and used routinely, for example, to measure ground movements in millimeters, map floods, or monitor subsidence over mines. In these applications, it excels.

Crucial is the penetration depth. Microwaves penetrate a few meters into dry sand, less into moist soil, and practically not at all into solid rock. The idea that a satellite could image structures hundreds of meters deep contradicts the physics of the method, regardless of how the data are processed afterward.

The research group relies on a special analysis intended to extract additional information from tiny vibrations of the ground. This exact analysis was the subject of the 2022 published and now withdrawn paper. The withdrawal followed an investigation initiated by the editor after a reader's comment.

For comparison, consider the method that worked at the same location. For the cavities in the Great Pyramid, muons from cosmic radiation were counted using detectors stationed inside the structure for months, operated by multiple institutes with different equipment. Publication occurred only after three independent measurement series showed the same results. This effort is why those findings have stood the test of time.

This does not mean every result from the group is false. It means the methodological foundation cannot currently be considered verified.

The Contradiction from the Scientific Community

The scientific community objected quickly and from multiple directions, and their objection concerns not whether something might lie there, but the analysis.

A frequently cited criticism is that structures are selected in the generated images while others are ignored, without any comprehensible criterion being apparent. If you look for shapes in noisy data, you will find shapes; the key is whether one can decide beforehand what counts as a discovery and what as noise. That decision is missing.

The second criticism comes from the relevant authority in Egypt. The former Minister of Antiquities stated publicly that the data are neither scientifically recognized nor validated, and there is no basis for facilities under the middle pyramid. Independent reviews of the 2025 claims reached the same conclusion.

The third point is formal. None of the three announcements have a peer-reviewed publication. They were presented at press conferences, in interviews, and on their own websites. This is not proof that the results are wrong, but it prevents the very review that would make them robust.

Noteworthy is also the impact history. The withdrawn paper was accessed very frequently before its withdrawal and cited countless times as evidence. A withdrawal no longer reaches that audience. Posts, videos, and articles relying on the work remain online and perpetuate the claim without mentioning the changed status. This is not an accusation against the authors, but a feature of the system.

Fairness dictates adding: The authors consider the withdrawal unjustified and have contested it. Such dissent is not unusual in withdrawals and does not change the publication's status.

Would a Second Sphinx Even Be Plausible?

Now for the more interesting question, lost in the excitement: Would a second Sphinx at Giza even be plausible?

There is a serious argument for it, and it has nothing to do with radar. Sphinxes often appear in pairs in Egypt, as guardian figures left and right of an entrance, and entire avenues of them flank temple routes. A single figure is rather the exception. If one assumes the architectural form, one may ask for a counterpart.

Against a counterpart at this specific location is geology. The known figure was carved from a rock outcrop standing exactly there, and the layers composing it are documented at its location. A second specimen would have required a second suitable outcrop. The surrounding pit has been cleared and surveyed without revealing anything comparable.

Additionally, there is the argument from excavation. The site has been an excavation area for over a hundred years, with sondages, boreholes, and geophysical measurements at many locations. A figure seventy meters long is not a small find that gets overlooked.

Another point argues against the specific interpretation. The images provided show a shape resembling the known Sphinx, in both size and outline. Exactly this is a warning sign in image analysis. If you search for a known shape, you are likely to find it in noisy data because the human eye fills in patterns. Robust features would be those no one expected, not those matching the template.

Nothing is thereby excluded. Large parts of the site are unexcavated, and in recent years, unknown cavities have indeed been detected using accepted methods. Just in the Great Pyramid, with muons, over months, and published.

This Changes Nothing for Your Visit

None of this changes anything for a visit, and that is the practical takeaway.

There is nothing to see at the site related to this claim. No excavation site, no barrier, no sign. Anyone driving there because of the news will find the known Sphinx in its enclosure and the same landscape around it as before.

Worth seeing instead is what genuine investigation looks like there. At several locations, excavation cuts are open, with profiles and markings. The difference between an image from a calculation operation and an exposed wall is immediately obvious on site.

It is also worth keeping scale in mind. The known, published finds of recent years are a thirty-meter cavity above a gallery and a nine-meter corridor behind a facade. Both took years, both were independently verified multiple times, and both are less spectacular than any headline.

One final note on context: Such news harms not only accuracy but also attention. While debate raged over a suspected second Sphinx, excavations were underway at the workers' settlement at the same site, a corridor behind the north facade of the Great Pyramid was viewed by camera for the first time, and a boat was transported to the museum in pieces. All three processes are documented, recorded, and more important for understanding the place than any radar report. They are significantly less well-known.

Those interested in what actually lies beneath the site are better served by excavation reports than by press conferences. They are duller and last longer.