They find evidence that the Earth hides remains of another planet inside

A newly discovered massive anomaly deep inside the Land It may be a remnant of the collision about 4.5 billion years ago that formed the Moon.

It is the conclusion of a new study, which was based on computational fluid dynamics methods pioneered by Professor Deng Hongping of the Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences, and is published as a featured cover in Nature this 2 of November.

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Prevailing theory has suggested that, during the later stages of Earth’s growth, approximately 4.5 billions of years, a massive collision, known as the “giant impact,” occurred between the primordial land (Gaia) and a Mars-sized protoplanet known as Theia. The moon is believed to have formed from the debris generated by this collision..

Numerical simulations have indicated that the moon probably inherited material mainly from Theia, while Gaiadue to its much greater mass, swas only slightly contaminated by material from Theia.

Since Gaia and Theia were relatively independent formations and were composed of different materials, theory suggested that the Moon (dominated by Theian material) and the Earth (dominated by Gaia material) should have different compositions. However, High-precision isotopic measurements later revealed that the compositions of the Earth and Moon are remarkably similarthus challenging the conventional theory of the formation of the Moon.

Although several refined models of the giant impact were subsequently proposed, all of them faced challenges.

To further refine the theory of lunar formation, Professor Deng began conducting research on the formation of the moon in 2017. He focused on developing a new computational fluid dynamics method called Finite Mass without Mesh (MFM), which excels at accurately modeling turbulence and material mixing.

Using this novel approach and performing numerous simulations of the giant impact, Professor Deng discovered that the Early Earth Exhibited Mantle Stratification After Impact, with the upper and lower mantle having different compositions and states. Specifically, the upper mantle featured a magma ocean, created by thorough mixing of material from Gaia and Theia, while the lower mantle remained largely solid and retained Gaia’s material composition.

“Previous research had placed too much emphasis on the structure of the debris disk (the precursor to the Moon) and had overlooked the impact of the giant collision on the early Earth.”Deng said in a statement.

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After conversations with geophysicists at the Swiss Federal Institute of Technology in Zurich, Professor Deng and his collaborators realized that this mantle stratification may have persisted to the present day, corresponding to global seismic reflectors in the middle mantle (located about 1,000 km below the Earth’s surface).

Specifically, Earth’s entire lower mantle may still be dominated by pre-impact Gaian materialwhich has a different elemental composition (including higher silicon content) than the upper mantle, according to a previous study by Professor Deng.

“Our findings challenge the traditional notion that the giant impact led to the homogenization of the early Earth.”said Professor Deng. “Instead, the giant impact that formed the moon appears to be the origin of the heterogeneity of the early mantle and marks the starting point of the geological evolution of the Earth over 4.5 billion years”.

Moon. (Photo: Pixabay)

Another example of the heterogeneity of Earth’s mantle are two anomalous regions, called Large Low Velocity Provinces (LLVP), that extend for thousands of kilometers at the base of the mantle. One lies beneath the African tectonic plate and the other beneath the Pacific tectonic plate. When seismic waves pass through these areas, the wave speed is significantly reduced.

LLVPs have important implications for the evolution of the mantle, the separation and aggregation of supercontinents, and the structures of Earth’s tectonic plates. However, its origins remain a mystery.

Dr. Yuan Qian of the California Institute of Technology, along with his collaborators, proposed that LLVPs could have evolved from a small amount of Theian material that entered Gaia’s lower mantle. They later invited Professor Deng to explore the distribution and state of Theian material deep in the Earth after the giant impact.

PART OF THEIA’S MANTLE JOINED THAT OF THE EARTH

Through in-depth analysis of previous simulations of giant impacts and performing new, higher-precision simulations, the research team found that A significant amount of material from Theia’s mantle, about 2% of Earth’s mass, entered Gaia’s lower mantle.

Professor Deng then invited computational astrophysicist Dr. Jacob Kegerreis to confirm this conclusion using traditional smoothed particle hydrodynamics (SPH) methods.

The research team also calculated that this material from Theia’s mantle, similar to lunar rocks, is enriched in iron, making it denser than the surrounding Gaia material. As a result, sank quickly to the bottom of the mantle and, in the course of prolonged mantle convection, formed two prominent LLVP regions. These LLVPs have remained stable throughout 4.5 billion years of geological evolution.

Heterogeneity in the deep mantle, either in the mid-mantle reflectors or in the base LLVPs, suggests that The interior of the Earth is far from being a uniform and “boring” system. In fact, small amounts of deep-seated heterogeneity can be brought to the surface by mantle plumes (cylindrical thermal updrafts caused by mantle convection), such as those that likely formed Hawaii and Iceland.

For example, geochemists studying the isotope ratios of rare gases in samples of Icelandic basalt have found that these samples contain different components from typical surface materials. These components are remains of heterogeneity in the deep mantle that date back more than 4.5 billion years and serve as keys to understanding the initial state of the Earth and even the formation of nearby planets.

According to Dr. Yuan, “Through precise analysis of a broader range of rock samples, combined with more refined giant impact models and Earth evolution models, we can infer the material composition and orbital dynamics of primordial Earth, Gaia and Theia. This allows us to constrain the entire history of the formation of the inner solar system”.

Source: Elcomercio