There’s a lot to learn here, and it’s critically important. The story of Theia’s collision is well explained by Anton Petrov in the video. It’s a fascinating story, and thank god for anyone who can explain it so clearly. The story, however, has a lot of practical issues to go with it.
The gigantic chunks of materials supposedly from Theia in Earth’s mantle are the big issues, and they are truly huge. These chunks are physically different, and denser than the mantle. There’s even an anomalous chunk of something on the Moon, sometimes called the remains of Theia, but perhaps a small remnant piece of the core? It’d be pretty easy to see if they’re similar. Not unlikely that they would be, given the history.
There are endless ramifications to these bits of information. One of the immediate applications of these supposed massive bits of Theia seems to be the South Atlantic Anomaly (SAA), which just happens to be trashing satellites with its electromagnetic field and is roughly the size of Western Europe. That’s as good a description as any of how important these bits of Theia are.
The formation of these chunks is fascinating. They’re distinct masses, and they’re in the liquid mass of Earth’s mantle. They may also be a clue to some of the weirder things in Earth’s history and its present. Our wandering north magnetic pole, for example, may or may not be part of this story.
There are some unknowns here:
• What happened to Theia’s core? What happens to a big mass, a planetary core, no less, when it crashes into another planet? My guess would be that Theia, because it was breaking up as it collided, was at a disadvantage in terms of relative mass. Earth’s solid inner core, incredibly dense, wasn’t affected, but Theia’s shattered.
• Theia’s core materials would have to behave completely differently from the rest of the planet’s mass. These core materials would be too dense and too heavy to simply dissolve.
• Why do the chunks exist where they do? Another theory – The big chunks obviously didn’t penetrate Earth’s core, but they sit on it. If you assume relative mass, that would explain the distinction between the mantle and the chunks.
• How do the chunks work? They’re materials of the same mass, in a liquid medium. That means they’re differentiated in the mantle liquid, and act differently from the liquid. In theory only, they’re partly in suspension, with the same specific gravity. (No huge leap of logic here. They couldn’t act otherwise.)
• What about the anomaly? Well, how about a sort of Archimedes theory – Electromagnetic fields can displace or neutralize other magnetic fields locally or on a big-picture basis. Big masses can generate those fields. The problem right now is that the displacement could play havoc with our planetary radiation suit, acting like a zipper, and opening it up. Not quite what we need, what with solar flares, etc.
• Do the chunks affect tectonic plates? They could, if they affect the crust, and that could well be the case, without stretching anyone’s basic understanding of geology at all.
The history of the chunks is also wide open to speculation, if not too many solid facts. What caused all those many episodes of huge vulcanism, some of which went on for millions of years?
Obviously, something atypical. How much more atypical than large chunks of another planet popping up to say hello under the crust do you expect to get? Not proven, but that said, there are many big geological events in Earth’s history which are vast and planet-changing. A few trillion tons of material in the mantle can’t be ruled out as possible causes, either.
One of the greatest learning opportunities and survival issues is right here. This is a built-in geophysical goldmine. There are major issues:
The South Atlantic Anomaly could be a huge issue in the future. This is an actual weakening of the Earth’s magnetic field. There’s only one way to do that – With another magnetic field and an extremely strong one. Likely candidates? Yep, we have a couple.
It’s growing. It happened in the geological blink of an eye, well within human lifetimes. It represents a potentially serious threat. Understanding it and learning how to deal with it could be crucial to the future of human technologies.
It’s also a working map of a planetary phenomenon never previously studied. (Only recently even suspected, in fact.) This is fundamental planetary physics in the raw.
The chunks may affect Earth’s rather patchy gravity. If you look at a gravity map of Earth, it’s a messy thing at best. There are areas of higher and lower gravity. Experts will say the chunks haven’t been related to this situation, but what if they are related? What if they move and change the gravity map? In theory, they should; but do they? (Interesting point; the SAA doesn’t register on the gravity map. Why not?)
A lot to learn, preferably fast
The chunks could be a whole new encyclopedia for geology, geophysics, astrophysics, radiation science physics, and practically anything to do with how the Earth works.
Also to be learned are how to deal with the various issues in geophysics. The SAA is already a major, expensive, issue, and it could expand. How to protect satellites is the obvious immediate issue, and information is required ASAP to deal with it.
How to deal with a sudden dysfunction in the radiation protection of the planet is another. The SAA region has the Van Allen Belts dipping down 200km, which is a huge, possibly dangerous dent in the radiation fields. As a fundamental problem of understanding, let alone management, this is the jackpot for the sciences. This could become a planetwide issue, or a series of problems in different areas if other anomalies show up.
The Theia chunks could also interact, as similar masses do in a liquid. They would have to behave in the same way, differentiated from the mantle liquid. What if they decide to hold a reunion sometime? What happens?
Also to the point in geochemistry – Why didn’t the two different cores homogenize? Why are they still separate entities? Does the mass effect override the chemical interactions?
So many of the huge geo events on Earth are exceptional. They’re gigantic planetwide events, and they need drivers. Not all volcanoes are Krakatoa, for example. What happens if you stick a large anomalous mass under a super volcano? These things don’t have any easy explanations. The chunks are hardly an easy answer, but the question needs to be asked.
Tracking the movements and behaviours of the chunks could be a revolution in the earth sciences. So many things are so unpredictable; what if they provide a tool for prediction?
This is all without even mentioning the basic planetary physics. If those chunks are Theia’s core, they must have different electromagnetic properties. That may explain why the mass doesn’t affect the gravity of the SAA, but its materials do? Do the chunks counteract the Earth’s electromagnetic field, neutralizing it?
If so, we may have a great way of managing electromagnetic fields, with a practical demonstration, right here. This is electromagnetic science, from quantum to macro, personified. Maybe there is a way of neutralizing or local counteracting the anomaly? Maybe someone should find out?
The Theia chunks could and should be the start of a whole new era in geophysics, and perhaps astrophysics. These massive chunks of history might be the Rosetta Stone for future sciences which don’t even exist yet. The theories now might be the 20 minute 101 for future science, too; this discovery is that basic, and that important.
Science often starts out with observations, becomes complex, and refines itself into a simple explanation, like Archimedes. Nothing about displacement is simple in terms of physics or mathematics; it’s the simple refined understanding that’s important. That’s exactly what’s needed with the chunks of Theia and their ramifications, and it could be as important, or even more important, than Archimedes’ theory.
