Part of the remains of the planet Theia, which is said to have collided with Earth when it formed, remains inside the Earth/Hernán Cañellas
2023.11.04 Sat posted at 12:25 JST
(CNN) When the Earth was forming billions of years ago, ancient planets collided, scattering fragments that coalesced to form the moon that colors the night sky today. Most scientists agree on this point.
This theory is called the “giant impact hypothesis” and explains many of the fundamental features of the moon and Earth.
However, until now, there has been no direct evidence of the existence of the planet Theia, which is said to have collided with Earth. No fragments of Theia have been found in the solar system, and many scientists believed that the remains of Theia left behind on Earth melted in the hot interior of the planet.
However, a new theory has emerged that suggests that parts of Theia’s remains remain, buried deep inside the Earth.
After impacting Earth, Theia’s molten mass sank into the mantle and solidified, according to a study published in the journal Nature on Tuesday. As a result, some of the material that made up Theia remained above the Earth’s core, about 2,900 kilometers underground.
An image depicting Theia colliding with the Earth in its early stages of formation.
If the theory is correct, it would not only provide new details to supplement the giant-impact hypothesis, but it could also answer geophysicists’ long-standing questions.
Scientists have already realized that there are two huge masses buried deep within the Earth. These clusters, called LLVPs (Large Low Velocity Regions), were first detected in the 1980s, and one is located under Africa, the other under the Pacific Ocean.
These masses are thousands of kilometers wide. Because it has a higher concentration of iron than the surrounding mantle, it can be detected by seismic wave measurements. However, scientists were not sure about the origin of the clumps.
