Mysterious 'Donut' Structure Found Hidden Inside Earth's Core

<img width="600" height="243" src="https://www.sciencealert.com/images/2022-05/processed/EarthCore_600.jpg" alt="Magnetism in Ancient Crystals Reveals When Earth's Inner Core Emerged"/>A strange anomaly where seismic waves slow down.

https://www.sciencealert.com/mysterious-donut-structure-found-hidden-inside-earths-core