4.5 billion years ago, a space body the size of Mars crashed into the newly formed planet Earth. The collision of the planet “Theia” (Theia) with the Earth was fierce while the debris that was launched into orbit, gradually joined and became a single body, the Moon.

Now scientists believe they have spotted pieces of “Theia” in the bowels of the Earth.

In their publication in the journal Nature, scientists from the California Institute of Technology, Caltech, led by geophysicist Qian Yuan, argue that during the impact, “Theia” left some of its material on the surface of the still-forming Earth. and that the debris “sunk” into our planet.

Scientists have known for decades that—toward the base of Earth’s mantle, near the boundary with the core—there are continent-sized chunks of denser material.

The study finds that today, two huge, dense chunks in the Earth’s mantle are essentially remnants of “Theia”.

Scientists used simulations of the impact, as well as the evolution of Earth’s interior, to identify where the remains of ‘Theia’ might be hiding and how they might have changed over time

“It’s a very exciting and challenging result,” planetary scientist Robin Canup of the Southwest Research Institute in Colorado enthused to National Geographic.

“This means we have material that can tell us more about Theia and help us better understand how the moon formed.”