Collision that formed the moon could be cause of mysterious blobs hidden in Earth

New research has suggested the collision that likely formed the moon could be responsible for another mystery on planet Earth.

The most widely agreed theory on how the Earth came to be is known as the giant-impact hypothesis. This theory, as the name implies, suggests that billions of years ago an ancient planet, called Theia, smashed into the Earth.

Scientists believe the debris from this collision went on to form the moon we see in the sky today.

Though there is one question that has baffled experts all over the world - what happened to the other fragments of Theia?

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A new study, that was published on Wednesday (1 November) in the journal Nature, has offered up an explanation.

Molten slabs of Theia could have embedded themselves within the Earth’s mantle after the impact before eventually solidifying, according to the theory.

These slabs are known by geologist and geophysicists and are two distinct blobs within the Earth’s mantle. These masses are called large low-velocity provinces (LLVPs) and were first detected in the 1980s underneath Africa and the Pacific Ocean.

According to the study, the two blobs are ‘compositionally distinct from the surrounding mantle’, thus strengthening the new theory.

“Direct evidence for the existence of Theia remains elusive. Here, we demonstrate that a fraction of Theia mantle mate-rial (TMM) could have entered the largely solid lower layer of the post-impact Earth’s mantle during the canonical Moon-forming impact,” the study states.

“This mostly molten TMM could later have solidified and sunk to Earth’s lowermost mantle and now constitute the seismically observed large low-velocity provinces (LLVPs)1 in the present day.”

Dr Qian Yuan, a geophysicist and postdoctoral fellow at the California Institute of Technology and the new study’s lead author, has explained that at this stage it is only a hypothesis, and he has invited others to do research on the topic, according to CNN.

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“I also want to stress this is an idea; this is a hypothesis. There’s no way to prove this must be the case. I welcome other people to do this [research],” he said.

Other theories that attempt to explain the mysterious blobs in the Earth’s mantle do exist and the debate around them is likely to continue despite this new theory.

One theory suggests that LLVPS are heaps of oceanic crust that have sunk to the mantel over billions of years, seemingly unconnected to the giant-impact theory.