The Earth’s core is an amazing, terrifying place. The inner core should be liquid, due to the immense heat, but the pressure is so intense it actually keeps it solid, for example. But that said, it’s not just a big-ass ball of nickel and iron; it turns out the inner core may have more layers than we thought.
Specifically, researchers from Nanjing University and the University of Illinois believe there’s an inner-inner core. The difference is in the structure; the team believes that while the inner core has a crystal structure that points north-south, the inner-inner core has a structure that points roughly east-west. This is thanks to a flip in the Earth’s magnetic field 500 million years ago.
Since we can’t exactly send a field trip down there, you might be wondering how researchers figured this out. The short answer is that they listened to earthquakes and how they changed as the waves moved through the various parts of the Earth. We bring this up because “Listener Of Earthquakes” should really be on their business cards.
Anyway, this is far from settled, as even the research team wants to have their work peer-reviewed and tested. But if it holds up, it will make for a fascinating peek into how the Earth has changed in the billion years it’s orbited the Sun.