The universe is vast and full of mysteries, many of which remain undiscovered. Surprisingly, scientists believe they may have identified a celestial body hidden right beneath our feet.
Indeed, it lies beneath the Earth’s surface.
This hypothesis is detailed in an article published in the journal Nature, where researchers present their evidence suggesting that an ancient planet named Theia played a crucial role in shaping Earth’s formation as we know it today.
Long before human existence, Theia is thought to have collided with Earth over four billion years ago, essentially merging with the planet and becoming part of our world.
The hypothesis suggests that the collision’s impact ejected magma from Earth’s mantle into space, which subsequently led to the formation of the moon.
While still a theory, scientists propose that Theia may have influenced continental formation, with remnants of the planet affecting Earth’s volcanic activity.
Researchers claim to have identified fragments of Theia when seismologists detected two continent-sized ‘basal mantle anomalies’—massive structures beneath the Earth’s crust—located under the Pacific Ocean and Africa.
These anomalies are denser than their surroundings, indicating they are composed of material different from the rest of Earth’s mantle.
By analyzing the anomalies in Earth’s mantle and comparing them with surrounding matter, the researchers propose these could be remnants of Theia’s mantle preserved deep within Earth, surviving billions of years after the moon-forming event.
To support this theory, the research team utilized simulations to show how a section of Theia’s mantle might have integrated into proto-Earth’s lower mantle.
Since Theia is believed to have had a higher density than Earth, finding moon samples matching the density and composition of these anomalies would support the idea that Theia collided with Earth, leading to the moon’s creation.
Additionally, the researchers highlighted the presence of zircon crystals on the moon, which are similarly found on Earth and Mars.
The team asserted that Theia’s remnants surviving deep within Earth would be expected as a result of the moon-forming giant impact.
They concluded: “Because giant impacts are common at the end stages of planet accretion, similar mantle heterogeneities caused by impacts may also exist in the interiors of other planetary bodies.”