Science Alert: [2] What goes down at the very center of our planet is largely a mystery, and so is what goes up.
[3] The truth is, no human has ever made it past the crust, or dug deep enough to penetrate Earth’s rocky mantle, let alone its liquid iron core, so we don’t know what type of interactions take place here. And that’s not for a lack of trying.
[4] Sitting at a depth of roughly 2,900 kilometres (1,800 miles), our planet’s core lies far beyond our technological reach – at least for now – and yet through educated guesswork and clever theoretical models, scientists have drawn a window into some of the enigmas lying beneath our feet.
[5] New research now suggests Earth’s molten core may actually be leaking iron into the upper mantle, which is more than a thousand degrees cooler than the liquid nucleus. [6] For decades, scientists have debated whether or not the core and the mantle exchange physical material.
[7] Earth’s powerful magnetic field and its electric currents certainly imply there’s lots of iron down in the core. Plus, samples of mantle rocks brought to the surface show a significant chunk of iron as well, leading some to speculate the material is coming all the way from the core.
To gain some insight into whether this could be possible, researchers have drawn on experiments in the lab showing how iron isotopes move between areas of different temperatures under high pressure and temperature.