Ancient Planet's Remnants Found in Earth's Deep Mantle

A study led by Caltech researchers suggests that the large low-velocity provinces (LLVPs) deep within Earth's mantle are remnants of an ancient planet called Theia, which collided with Earth billions of years ago and also contributed to the formation of the Moon. These LLVPs, discovered in the 1980s, are massive iron-rich structures that are denser than their surroundings. The study's simulations show that Theia's mantle material clumped together and crystallized to form the LLVPs, while other debris from the collision coalesced to create the Moon. This discovery sheds light on the origin of the Moon and raises questions about the influence of Theia's material on Earth's early evolution.