Key Takeaways:
- Scientists believe a Mars-sized planet called Theia collided with early Earth, forming our planet and the Moon.
- New research suggests parts of Theia’s mantle might still exist as dense regions deep within Earth’s interior.
- Due to their density, these Theia remnants are theorized to have sunk to Earth’s lower mantle.
- These dense regions correspond to the “continent-sized Large Low Shear Velocity provinces (LLSVPs)” observed in Earth’s mantle.
- Studying these LLSVPs could provide insights into Earth’s formation, the Moon’s origin, and deep mantle dynamics.
According to a research, scientists theorize that Theia, a wandering planet the size of Mars, formed Earth, with recognizable remains of the alien planet still present in the planet’s interior.
This is the first time researchers have examined the precise parts of the collision that are still present in the Earth’s mantle, despite the fact scientists think the same catastrophic impact also created the moon.
In 2016, UCLA researchers proposed that Earth could actually be two planets that fused together after colliding: itself and Theia. Scientists at the time stated that they thought the two planetary masses blended together evenly. According to Qian Yuan of Arizona State University and his associates, the pieces of Theia that remain intact could be found in the mysterious dense spots deep within Earth’s interior.
At the 52nd Lunar and Planetary Science Conference earlier this month, Yuan’s team gave a paper presentation. They clarify in it:
“Here, we demonstrate that Theia’s mantle may be several percent intrinsically denser than Earth’s mantle, which enables the Theia mantle materials to sink to the Earth’s lowermost mantle and accumulate into thermochemical piles that may cause the seismically-observed [dense areas].”
“Continent-sized Large Low Shear Velocity provinces (LLSVPs)” are these crowded areas.
Scientists from Arizona State University located particular regions of the Earth’s interior and created a model to explain how these regions might have collided with the early Earth and sank into its center:
“We define successful models in which the [Theia mantle materials] sink to the lowermost mantle and form into spatially isolated thermochemical piles that occupy 3-15% area of the 2D model domain, similar to the present-day LLSVPs which occupy ~3-9 vol% of the Earth’s mantle.”
In an interview with Vice, Yuan talked about getting a bolt of inspiration after chatting with a colleague about LLSVPs. “When I got back to my office,” Yuan said, “I just did a very easy calculation where I compared the size of the LLSVPs to the mantle of Mars, because Theia was believed to be very similar to Mars. The combined mass of the moon and the LLSVPs nearly exactly matches the mantle of Mars.
For billions of years, how have the dense materials of Theia remained intact? It is a result of the way convection moves materials with a particular density and temperature through the Earth’s mantle. Because of their extreme density, the Theia materials sank and were never able to float back into the convection zone. Consider this as the debris that builds up in a tight space that is difficult to clean with a vacuum.
What does it mean that these materials will remain in the Earth’s interior? Since the “continent-sized” regions make up the majority of the interior of Earth, learning more about how they developed and continue could advance Earth science. These two enormous parts, which are hundreds of miles thick, are situated beneath the Pacific Ocean and West Africa, according to HuffPost.
Because of their possible similar origin story, there may also be intriguing parallels to “unearth,” so to speak, between the moon and these dense mantle portions. How often can you make a comparison between a rock sample that is 4.5 billion years old and one that is buried deep inside the Earth? It’s the realization of a scientific method dream.
