Deep beneath Africa, scientists say two colossal structures are hiding near the boundary between Earth’s mantle and core, and some researchers now argue that these buried giants may be relics of an ancient planet like Theia that collided with the early Earth. I see these findings as a rare moment when seismology, planetary science and the story of how our world formed converge on a single, audacious possibility: that parts of another world are still entombed under our feet.
The First Colossal Structure Beneath Africa
The first colossal structure beneath Africa emerges in seismic data as a vast, dense region perched above the core, and researchers studying it have proposed that this anomaly could be a surviving fragment of an ancient impactor planet such as Theia. According to reporting on how scientists uncover two colossal structures beneath Africa, this deep feature is interpreted as part of a pair of giant formations that sit thousands of kilometers below the surface, close to the core mantle boundary where pressures and temperatures are extreme. I understand this first structure as one half of a planetary scale puzzle, because it appears to be chemically and physically distinct from the surrounding mantle, which is why some geophysicists argue that it may not be from this world at all. In their view, the early Earth’s violent collision with a Mars sized body, often called Theia, could have left behind dense, iron rich or chemically exotic debris that sank toward the core and pooled into the immense blob now detected beneath Africa. That interpretation, if correct, would mean that the African structure is not just a mantle irregularity but a preserved shard of a lost planet, still influencing how heat and material move through Earth’s interior.
To appreciate the scale and stakes of this first structure, I focus on how it reshapes our understanding of both deep Earth dynamics and planetary history. Seismic waves from earthquakes slow down and bend as they pass through this African anomaly, signaling that it is hotter or compositionally different from the surrounding rock, and the reporting that describes two colossal structures beneath Africa that may not be of this world emphasizes that these differences are so pronounced that standard models of mantle convection struggle to explain them. I interpret that mismatch as a clue that the structure may contain material with a unique origin, perhaps enriched in elements that were more abundant in Theia than in the proto Earth, which would help explain why it remains so coherent instead of being stirred away by billions of years of mantle flow. The implications extend far beyond academic curiosity, because this deep reservoir likely affects where superplumes rise, how hotspots like those feeding African volcanism are sustained, and even how Earth’s magnetic field interacts with heat flow at the core boundary. If the first colossal structure is indeed a remnant of Theia, then every volcanic eruption linked to African mantle upwellings could be, in part, the surface expression of an ancient planetary collision, turning a remote geophysical anomaly into a key actor in the long term evolution of continents, climate and habitability.
The Second Colossal Structure Beneath Africa
The second colossal structure beneath Africa appears in the same seismic reconstructions as a companion to the first, another giant mystery formation lurking deep under the continent that reinforces the idea of an otherworldly origin. Coverage describing how scientists have discovered two giant mystery structures lurking under Africa presents this second feature as part of a matched pair, both of them enormous, dense and anomalous compared with the surrounding mantle. I interpret this twin configuration as crucial, because it suggests that the deep interior did not simply develop one isolated blob through random convection, but instead organized two massive structures that may trace the distribution of impact debris from an early planetary collision. In that scenario, the second structure would represent another concentration of Theia derived material, perhaps with slightly different composition or temperature, yet still distinct enough to stand out in seismic data. The fact that geophysicists can map both structures independently, and still see them as parts of a coherent pattern, strengthens the case that they are not transient features but long lived reservoirs that have survived since the earliest chapters of Earth’s history.
When I consider the broader implications of this second structure, I see it as a test of how far scientists can push the link between deep Earth imaging and planetary formation models. The reporting that scientists discover two colossal structures beneath Africa and argue that they may not be of this world frames both anomalies as evidence that the early Earth did not fully homogenize after the Theia impact, leaving behind chemically distinct domains that still shape mantle circulation. I view the second structure as especially important for stakeholders in geohazard assessment and resource exploration, because its presence can influence where mantle plumes rise, how rifting in East Africa evolves and where deep sourced magmas bring metals and volatiles toward the crust. For planetary scientists, the existence of a second, equally colossal anomaly provides a natural laboratory for testing simulations of giant impacts, since any successful model must now reproduce not just a Moon forming collision but also the creation and long term survival of two deep reservoirs under Africa. In that sense, the second structure is more than a curiosity, it is a constraint on theories of how rocky planets assemble, mix and retain traces of their most violent encounters, and it keeps open the provocative possibility that fragments of another world are still quietly shaping the geology and geophysics of the African continent from thousands of kilometers below.
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