Filippo Biondi and Corrado Malanga have applied satellite-based radar tomography to the Great Pyramid of Giza and reported imaging previously unknown internal structures, a claim that now sits alongside peer-reviewed discoveries of a roughly 30-meter void inside the pyramid and a shallow L-shaped anomaly at the nearby Western Cemetery. The findings, drawn from COSMO-SkyMed 2nd generation satellite data and processed through synthetic aperture radar Doppler tomography, have not yet passed peer review, placing them in tension with validated results from muon detectors and ground-penetrating radar surveys conducted between 2021 and 2023. Whether these satellite signals reflect constructed chambers or natural geological features is the question driving the next phase of investigation at Giza.
Why satellite radar claims at Giza demand scrutiny right now
Three independent lines of evidence now point to hidden spaces in and around the Great Pyramid, but they differ sharply in scientific rigor. The strongest result comes from cosmic-ray muon detectors, which identified a void with a minimum size of approximately 30 meters inside Khufu’s Pyramid and published the result in Nature after extensive cross-validation. A separate corridor on the pyramid’s north face was later confirmed through multimodal image fusion combining three non-destructive testing techniques, as documented in a Scientific Reports investigation. Those two discoveries set a high bar for what counts as a verified hidden structure at Giza, because they rely on redundant instruments, transparent data, and peer-reviewed analysis.
The satellite-based claims from Biondi and Malanga have not cleared that bar. Their technical paper, posted on the arXiv preprint server, describes using COSMO-SkyMed 2nd generation SAR data to produce tomographic images of the pyramid’s interior. The method is novel, but the raw datasets and processing code have not been released for independent reanalysis, leaving other researchers unable to test the robustness of the signal processing chain or to explore alternative interpretations. No peer-reviewed journal has evaluated the SAR Doppler tomography results, and Egyptian antiquities authorities have not publicly confirmed or disputed the deeper anomalies the paper describes.
A separate ground-level survey adds context. Between 2021 and 2023, researchers conducted a geophysical exploration at the Western Cemetery adjacent to the pyramids using ground-penetrating radar and electrical resistivity tomography. That peer-reviewed study, published in Archaeological Prospection, identified a shallow L-shaped feature measuring roughly 10 by 10 meters at modest depth. The Western Cemetery results demonstrate what established near-surface geophysics can credibly resolve at Giza, and they highlight the gap between ground-truth confirmation and orbital radar interpretation.
Muon detectors, ground radar, and satellite SAR produce conflicting confidence levels
The three detection methods operate at very different scales and levels of proven reliability. Muon radiography works by tracking cosmic-ray particles that lose energy as they pass through stone, producing density maps of a structure’s interior. The technique detected the so‑called Big Void inside Khufu’s Pyramid using multiple independent detector arrays, a redundancy that strengthened the finding before publication. The North Face Corridor confirmation followed a similar pattern, combining three non-destructive testing methods to cross-check a single structural claim and presenting the results in a way that allowed other specialists to evaluate the data.
Satellite SAR tomography, by contrast, sends microwave pulses from orbit and reconstructs subsurface features from the reflected signals. Biondi and Malanga argue the technique can resolve internal details at high resolution by exploiting multiple orbital passes and Doppler diversity. But SAR signals passing through limestone and sand can produce artifacts that mimic voids or corridors, especially when scattering, moisture variations, and surface roughness are imperfectly modeled. The linear features detected by satellite radar could represent natural karst drainage channels rather than constructed chambers. Karst formations are common in many limestone plateaus and can carve elongated cavities and conduits that, in radar data, resemble human-made tunnels. Distinguishing them from ancient architecture requires ground-truth data that the satellite study does not provide.
The Western Cemetery GPR survey offers a partial bridge between these approaches. Ground-penetrating radar operates at close range with higher spatial resolution than orbital SAR, and the peer-reviewed results from that 2021 to 2023 campaign produced a clearly imaged shallow anomaly with defined dimensions and geometry consistent with a built structure or prepared space. Deeper signals were also detected, but detailed coordinates and depth estimates beyond the published abstract have not been released, limiting how precisely other teams can design follow-up work. The gap between what GPR resolved at shallow depth and what satellite SAR claims to see at greater depth is where the scientific debate now sits, with some researchers urging caution until independent teams can reproduce the orbital signatures.
What drilling and isotopic analysis could settle about Giza’s subsurface
The most direct way to resolve whether the satellite radar anomalies represent human-made chambers or natural geology is targeted shallow drilling. Carefully positioned boreholes, aligned with the strongest SAR anomalies and any overlapping GPR or resistivity hints, could retrieve continuous core samples from the limestone and any intervening voids. Those cores would then be available for petrographic inspection, microstructural analysis, and geochemical testing, providing a physical record of how the rock mass formed and whether it has been modified.
Isotopic analysis would be central to that effort. Karst channels leave distinct chemical signatures in limestone, including patterns associated with prolonged water contact, recrystallization, and the introduction of dissolved ions. Ratios of oxygen and carbon isotopes, for example, can help distinguish rock that has been altered by groundwater flow from blocks that were quarried, transported, and reassembled in a pyramid wall. Constructed chambers, by contrast, tend to show clean-cut tool marks, straight bedding discontinuities, and fill materials such as mortar, rubble, or sand that match known ancient building practices. If a borehole intersects such a space, even a narrow core could reveal unmistakable traces of human engineering.
Drilling would also permit radiometric dating of any secondary deposits, such as calcite crusts or infill sediments, constraining when voids opened or were last accessible. If a cavity proves to be natural and predates the pyramid by hundreds of thousands of years, that would support the karst interpretation and suggest that some internal spaces are inherited geological features the builders either avoided or incorporated. If, instead, the isotopic and stratigraphic evidence points to anthropogenic excavation contemporaneous with Khufu’s reign, the case for deliberate hidden chambers would strengthen dramatically.
No drilling campaign has been announced, and any such work would require approval from Egyptian authorities, coordination with conservation experts, and a clear plan to minimize risk to the monument. The absence of direct statements from those authorities about the deeper anomalies is itself a significant gap, leaving outside observers to infer priorities from published studies rather than official project roadmaps. Until ground-truth verification occurs, the satellite radar findings occupy an intermediate space: technically interesting but unconfirmed, and sitting well below the evidentiary standard that muon detectors and peer-reviewed GPR and resistivity surveys have already met at Giza.
For now, the most responsible stance is to treat the Biondi–Malanga tomography as a provocative hypothesis generator rather than a map of hidden rooms. Their orbital approach could, in principle, complement muon radiography and ground-based geophysics by flagging zones of unusual scattering for closer inspection. But the history of remote sensing in archaeology is full of false positives when imagery races ahead of excavation. As the Great Pyramid continues to attract new technologies, the lesson from recent successes is clear: robust discoveries emerge when multiple independent methods converge on the same feature and when interpretations are anchored to verifiable material evidence in the rock itself.
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*This article was researched with the help of AI, with human editors creating the final content.
