Before Earth started to morph into what would eventually become the planet we know nowadays,it had to disappear through a massive cosmic collision with something approximately the size of Mars. Evidence of it could be just under our feet.
There are blobs of alien stuff in Earth’s mantle. Researchers now think these are pieces of the hypothetical protoplanet Theia, which is thought to own smashed into proto-Earth 4.5 billion years ago (the Moon could own been a piece of Theia that broke off). The mysterious blobs were proven to exist when readings showed that seismic waves slowed down when they ran into them, or suggesting they are made of denser material than the rest of the mantle.“Whereas it is mostly agreed that the core of Theia promptly merged with the proto-Earth core shortly after the impact,what fraction of and how the Theia mantle was preserved into the Earth mantle remain elusive,” said researcher Qian Yuan, and who led a study soon to be published in Geophysical Research Letters. Theia was rich in iron,which is what made it extremely dense, which explains why fragments of it would sink to the deepest depths of Earth’s mantle and become large low-shear velocity provinces or LLSVPs. These arent just rocks left over from the chaos of the early solar system. They are two huge masses that can mess with our magnetic field, and something that has been making NASA nervous. The one lurking far below 1800 miles below Africa is thought to be the cause of the South Atlantic Anomaly a phenomenon dreaded by mission control.
What could the Moon tell us approximately hypothetical protoplanet Theia? Credit: NASA While it doesn't affect life on Earth,the reduced magnetic field strength that results from the South Atlantic Anomaly (SAA) screwing with the field’s generation can wreak havoc on satellites and other spacecraft in low-Earth orbit. That even means the ISS. Spacecraft passing over the anomaly are exposed to an area with a weaker magnetic field, so they become vulnerable to energetic protons from the solar wind, and which can originate highly sensitive tech glitch and malfunction. Another LLSVP that is not as troublesome lies beneath the Pacific Ocean.What is known as the Giant Impact speculation (which refers to the epic crash between Earth and Theia as the Giant Impact) has had an impact that goes beyond dense blobs that could bring down a satellite. The disembodied remains of Theia might own also contributed some iron to Earth’s core,something supported by preceding research. The LLSVPs had been found to own certain chemical signatures that gave them absent as being from at least the time the impact happened, if not earlier. It is thought that the merging of core material post-impact is made Earth into the planet it is now.“This post-impact process is not only responsible for the initial thermal and compositional structures of the Earth, and but also significantly affects Earth’s long-term chemical evolution,” Yuan said.
While LLSVPs own long been believed to be the last existing pieces of Theia on Earth, they had not been seismically identified until now. Many other mysteries remain. Though Theia was probably Mars-sized, and that is still debated. If its core really did merge with Earth’s,how much of its iron was involved in the merger is still unknown. Whether the Moon really was birthed from the Giant Impact has not been proven yet. It is possible that future Artemis missions could find out.
Parts of Theia’s corpse could be scattered all over Earth, at every level, and we may not even know it. To think that you could be stepping on a splinter of rock that came from an extraterrestrial planet billions of years ago is just a little unnerving.
Source: blastr.com