The Mystery of Theia: Remnants of Ancient Planet May Be Buried Beneath Earth’s Surface
Scientists have long believed that an ancient planet, called Theia, collided with Earth billions of years ago, leading to the formation of the moon. However, direct evidence of Theia’s existence has been elusive, leaving a lingering mystery in the scientific community. But a new theory suggests that remnants of the ancient planet may still be buried deep within Earth’s mantle.
According to a study published in the journal Nature, molten slabs of Theia could have embedded themselves within Earth’s mantle after the impact, before solidifying and leaving portions of the ancient planet’s material resting above Earth’s core, approximately 1,800 miles below the surface. This theory not only provides additional details to support the giant-impact hypothesis but also answers a lingering question for geophysicists.
Scientists have been aware of two massive, distinct blobs embedded deep within the Earth, known as large low-velocity provinces (LLVPs), since the 1980s. These blobs, one beneath Africa and the other below the Pacific Ocean, are thousands of kilometers wide and have a higher density of iron compared to the surrounding mantle. However, their origins have remained a mystery.
Dr. Qian Yuan, a geophysicist and the lead author of the study, made a breakthrough when he connected the dots between Theia and the LLVPs. Initially, Yuan was hesitant to share his theory with others, fearing they would think it was too crazy. However, he eventually proposed his idea in a paper and sought to find evidence to support it.
Yuan’s theory was based on the idea that Theia’s collision with Earth did not entirely melt the mantle, allowing remnants of the ancient planet to cool and form solid structures instead of blending together within Earth’s interior. Researchers conducted higher-definition modeling and found that if Theia were a specific size and consistency and struck Earth at a certain speed, it could have left behind large chunks of its material within Earth’s mantle.
The study received support from coauthors across various institutions, including Arizona State University, Caltech, the Shanghai Astronomical Observatory, and NASA’s Ames Research Center. While Yuan acknowledges that his theory is just an idea and a hypothesis, other scientists in the field have found the research compelling.
However, not all scientists are convinced. Dr. Seth Jacobson, an assistant professor of planetary science at Michigan State University, believes that the theory may not soon reach broad acceptance. He points out that the idea that Theia created the LLVPs is just one hypothesis among many. Jacobson anticipates that the scientific community will continue to debate the origin of the LLVPs for quite some time.
The discovery of remnants from an ancient extraterrestrial planet buried within Earth’s mantle would provide valuable insights into the formation and evolution of our planet. As scientists continue to explore the mysteries of the universe, the search for answers about Theia and its impact on Earth’s history remains an exciting and ongoing endeavor.