The Moon formed after the ancient Earth collided with a Mars-sized body known to scientists as Theia. The cosmic collapse occurred about 4.5 billion years ago, but its effects are still being felt today; Not only the Moon, but also observable structures in the Earth’s mantle preserve traces of the former strange celestial body.
For a long time, the prevailing opinion was that the face of the Earth also changed after the impact, but not as radically as the face of Theia, which was completely destroyed as a result of the disaster, and from the adhesion of its surface to it. Debris, our celestial companion, the Moon, was born over time. If that were the case, the chemical composition of the Earth and the Moon would be different, but this is not the case. The latest simulations indicate that it is also possible to find traces of Theia underground.
The researchers used a simulation technique that ideally models the mixing of materials that occurs during planetary collisions.
Based on the results, Theia caused more widespread changes on Earth than previously thought.
What does the depth of the earth hide?
“Previous research has overemphasized the structure of the debris disk (the Moon’s predecessor) and neglected the impact of the giant impact on the early Earth,” Deng Hongping, a professor at the Shanghai Astronomical Observatory, said in a statement. According to the researcher, the heterogeneity of the early Earth’s mantle is due to the impact of Theia 4.5 billion years ago, and this event can be considered the starting point of geological evolution that has been going on for billions of years.
Simulations show that after the collision, the upper and lower mantle changed into different compositions and states.
The lower part of the mantle is mostly solid, with little contamination from Theia; Approximately two percent of the material of the impacting body penetrated this depth. However, the upper mantle is a mixture of materials from the early Earth and Theia.
Theia material in the Earth’s lower mantle may be responsible for the so-called formation of low-velocity regions (LLVPs). The latter are structures found in the mantle beneath the African and Pacific tectonic plates. It is possible that the material in Theia sank to depths because it is rich in iron and therefore heavier than the surrounding material.
However, more research is needed to confirm the theory. Through volcanic processes, material can seep to the surface from lower regions of the mantle, and even from the Earth’s interior. By examining this, they can confirm or disprove the theories just proposed. Moreover, with the help of the results, we were able to solve the mysteries of the formation of not only the Earth, but also other rocky planets.
The complete study is A nature It can be read in a scientific journal.
