Earth’s origins within our solar system may be even more mysterious than previously thought. Scientists from the California Institute of Technology published a new theory about two massive “blobs” in the inner part of the planet. For decades, there have been discussions about what these formations are. The new theory comes to only one conclusion – hidden inside the globe are the remains of an ancient and forgotten planet.
In the 1980s, scientists were surprised to discover two huge “spots” deep in the Earth, each larger than the Moon. The “spots,” one under the African continent and the other under the Pacific Ocean, exhibited unusual properties compared to their surroundings.
Large areas with low speed
These structures, known as large areas with low speed (large low-velocity provinces; LLVP), have puzzled scientists studying the Earth, its origin and internal arrangement. These places are of interest to geophysicists because the low speed of seismic waves suggests that these regions may have different properties compared to surrounding regions of the Earth’s mantle, such as a higher temperature or a different chemical composition.
A new study published on Wednesday, November 1 in the scientific journal Nature comes up with a fascinating theory: these “spots” are the remnants of a planet that collided with Earth billions of years ago. This colossal impact is believed to have been the same event that gave rise to the Moon. Next details are provided by the StudyFinds website.
For a better understanding, it is important to know that seismic waves, which are energy waves propagating through the Earth, behave differently when meeting different materials. In the 1980s, scientists discovered that seismic waves slow down significantly when passing through certain areas deep in the Earth’s mantle, leading to the discovery of the LLVP. These areas are believed to contain a higher proportion of ironmaking them denser and causing seismic waves to slow down.
The collision that created the moon
Geophysicist Qian Yuan recalls the moment of discovery during a seminar in 2019. The seminar, led by Professor Mikhail Zolotov of Arizona State University, discussed the giant impact hypothesis – a theory that posits that the Moon was formed after a massive collision between Earth and a smaller planet called Theia . However, no trace of Theia was ever found.
“Right after Mikhail stated that no one knew where the impactor was now, I had a ‘eureka moment’ and realized that an iron-rich impactor may have turned into blocks in the mantle,“ says Yuan in a university press release.
Through extensive modeling and simulations, the science team was able to confirm that the collision could have given rise to both the Moon and the LLVP. Part of Theia’s mantle may have merged with Earth’s mantle, eventually creating the two separate “spots” we see today. The rest of the debris from the collision subsequently coalesced to form the Moon.
What did the simulations show?
The question naturally arises: why did the material from Theia form into two separate “blobs” instead of mixing evenly with the Earth’s mantle? The simulations performed showed that much of the energy from the collision remained in the upper half of the mantle.
This left the lower parts of the mantle relatively cooler, allowing the iron-rich material from the planet Theia to remain largely intact and settle in the higher part of the mantle, much like droplets in a lava lamp.
“The logical consequence of the idea that the LLVPs are the remains of the planet Theia is that they are very old,” says one of the study’s co-authors, Paul Asimow. „It therefore makes sense to further investigate what consequences they had for the earliest development of the Earth before the conditions were suitable for plate tectonics of the modern type, the formation of the first continents and the origin of the oldest extant terrestrial minerals.”
2023-11-05 15:46:52
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