According to researchers, enigmatic masses residing over 1,000 miles beneath the surface could potentially be leftovers from a planet the size of Mars that collided with Earth during the early stages of the solar system. This collision would have resulted in a cascade of debris that eventually formed our moon.

Scientists believe that the moon formed approximately 4.5 billion years ago through the collision of an early protoplanet called Theia with a young Earth. This event occurred when Earth was still in its early stages and was only 85% of its current size.

The hypothetical impact would have caused significant melting of both Earth and Theia, resulting in the formation of a larger, fused Earth. At the same time, a large quantity of dust and debris was ejected into orbit and eventually coalesced to form the moon.

Although the giant impact theory is widely accepted among scientists, they are still searching for evidence to further support this idea. This includes any signs of a forceful collision that may still be observable today.

Taking this into consideration, a group of scientists from different countries focused on investigating two enormous masses located in the inner layers of the Earth, under Africa and the Pacific Ocean. These masses, scientifically referred to as large low-velocity provinces (LLVPs), were first identified by seismologists but their origins have always been a mystery.

The team of researchers, led by Dr. Qian Yuan from the California Institute of Technology in Pasadena and Prof. Hongping Deng from the Shanghai Astronomical Observatory (part of the Chinese Academy of Sciences), employed computer simulations to investigate the process of a massive impact and the resulting convection currents within Earth. They aimed to understand the potential sequence of events during this catastrophic event.

Based on the simulations, the impact would have caused the top portion of the Earth’s mantle to melt, allowing a significant portion of Theia, potentially 10%, to penetrate deeper into the planet and gradually descend towards the core.

Within the next 4.5 billion years, Theia’s rock may have shifted due to Earth’s internal convection, eventually leading to the creation of the current blobs. These blobs are believed to be slightly more dense than the surrounding mantle rock and are located near the border between Earth’s core and mantle, approximately 1,800 miles below the surface.

According to Yuan’s statement to the Guardian, our work is the initial proposal of this concept. The specifics have been published in the journal Nature.

Scientists may need a significant amount of moon rocks to determine if the buried blobs are leftovers from the ancient Theia. These rocks could be obtained in the future as space agencies continue to pursue establishing a permanent presence on the moon in preparation for future missions to Mars.

Yuan expressed excitement for upcoming moon missions that aim to retrieve mantle rocks believed to have originated from Theia, based on simulations of the moon’s formation. If the chemical makeup of the lunar mantle rocks and LLVP-related basalts are similar, it further supports the idea that they both came from Theia.

Professor Alex Halliday, an expert in planetary evolution and materials at the University of Oxford, and also a professor of earth and environmental sciences at Columbia University in New York, commended the paper. However, he noted that further research is needed to fully understand the processes responsible for the diverse composition of the deep mantle and the similar isotopic signatures between the Earth and moon.

“He praised the paper for its innovative ideas and intriguing findings. However, it also brings up important questions that require further exploration and examination, particularly regarding how the moon and Earth interacted to produce numerous resemblances while still maintaining ancient deep-mantle differences.”

Source: theguardian.com