Ancient planetary remnants may lie deep within Earth's mantle
For years, scientists have been pondering the mysterious structures deep within the Earth. Research indicates that they are billions of years old. Could these be remnants of an ancient planet that once collided with Earth?
Scientists have discovered that two enormous structures deep within the Earth may have remained stable for billions of years, reports New Scientist. The analysis of seismic waves that travel through the planet points to their remarkable durability.
Beneath the surface of our planet, at a depth of about 2,900 kilometres, lie enigmatic objects. These extraordinary formations are located at opposite ends of the Earth: one under the region of Africa, and the other beneath the central part of the Pacific Ocean.
Seismographic analysis has provided new information
Arwen Deuss from Utrecht University explains that during a major earthquake, the entire Earth vibrates like a bell. These vibrations have allowed for the identification of two continental structures that extend almost 1,000 kilometres from the outer core to the lower mantle of the Earth.
The structures are termed "large low-shear-velocity provinces" (LLSVPs). They remain a mystery, and we know little about their composition or origin. Recent analyses suggest that these areas do not absorb seismic waves in the previously predicted way, indicating the presence of minerals with a distinctive crystalline structure.
The stability of these structures may indicate that they are extraordinarily old. Scientists speculate that their formation can be dated to the early stages of our planet's development, over 4 billion years ago. They may serve as reservoirs of primordial material occasionally reaching the surface through volcanoes. Research published in "Nature" suggests that these structures could be crucial to understanding our planet's history. Their analysis provides new information about these mysterious formations' temperature, composition, and shape.
Remnants of a prehistoric collision
New research suggests that the mysterious spots in the Earth's mantle may be remnants of the ancient planet Theia, which collided with Earth about 4.5 billion years ago. Experts had thought that little remained of Theia, from which the Moon was formed, but new evidence points to its presence inside the Earth. A team of scientists from China, the USA, and the United Kingdom presented evidence of Theia's remnants not only on the Moon but also within the Earth. The research suggests that about 2-3% of Earth's mass could originate from Theia, and the spots beneath the tectonic plates may have evolved from its material.
The turbulent history of Earth
Studies of lava from volcanoes in Samoa and Iceland indicate that these structures differ from the surrounding Earth's mantle, suggesting their extraterrestrial origin. The theory of a collision with a lost planet confirms the turbulent history of Earth and may explain the stratification of the Earth's mantle.
