Earth’s Mantle May Contain Evidence of a Planetary Collision that Formed Our Moon

Researchers at Arizona State University’s School of Earth and Space Exploration published a new paper in that may provide answers for why there are two continent-sized “blobs” hidden within the Earth’s mantle. The new research suggests the blobs, which were first discovered in the 1980s, may be remnants of a long-gone planet named Theia. This planet was thought to have crashed into Earth during the early days of our solar system, breaking apart and creating our Moon.

Concept art of Theia crashing into an early Earth. Credit: NASA/JPL-Caltech.

Lunar Formation

Astronomers have several theories on why Earth has a moon, although one is much more widely accepted than the others. The first is known as the fission theory, which states that the Moon may be a piece of Earth that broke off during its formation due to speedy rotation. Similarly, another theory called the co-creation theory suggests that the Moon formed at the same time as Earth out of the same material. Both of these theories tend to be overlooked, as the Moon’s composition is not similar enough to Earth’s.

Another theory of lunar formation is the capture theory. The basic idea is that the Moon was already formed and simply pulled into orbit by Earth’s gravity during a close encounter during the formation of the solar system. The main flaw with this theory is that…