Beneath the Earth’s surface lies a world of wonders, from vast hidden oceans to water that seeps into the core itself. The latest discovery, however, stands out as particularly captivating. Recent research has uncovered compelling evidence near the Earth’s core, believed to be remnants of an ancient planet.
This planet, known as Theia, is thought to have collided with Earth billions of years ago, with signs of this colossal impact identified in two deep subterranean masses. Since their initial discovery in the 1980s, these masses have intrigued scientists. These continent-sized structures are about double the size of the moon.
Found under Africa and the Pacific Ocean, their high iron content slows seismic waves, earning them the name “large low-velocity provinces” (LLVPs). A study published at the close of 2023 in the journal “Nature” by researchers from Caltech has brought new insights into these LLVPs.
Study suggests Earth’s deep structures are remains of ancient planet Theia
Most significantly, the study argues that these structures, which have divided opinion for decades, are the remains of Theia, which collided with Earth billions of years ago. This collision caused the creation of the moon, and the new study argues that the planet was absorbed into the Earth and formed the LLVPs.
“Seismic images of Earth’s interior have revealed two continent-sized anomalies with low seismic velocities, known as the large low-velocity provinces (LLVPs), in the lowermost mantle,” researchers wrote.
“The LLVPs are often interpreted as intrinsically dense heterogeneities that are compositionally distinct from the surrounding mantle.”
They added: “Here we show that LLVPs may represent buried relics of Theia mantle material (TMM) that was preserved in proto-Earth’s mantle after the Moon-forming giant impact.
“Our canonical giant-impact simulations show that a fraction of Theia’s mantle could have been delivered to proto-Earth’s solid lower mantle.”
