Mysterious ‘Donut’ Structure Found Hidden Inside Earth’s Core ScienceAlertDoughnut-shaped region found inside Earth’s core deepens understanding of planet’s magnetic field Phys.orgVast ‘doughnut’ discovered in molten metal of Earth’s core The GuardianScientists Unveil Doughnut-Shaped Structure Hidden In Earth’s Outer Core NDTVDoughnut-shaped region thousands of mile below Earth’s surface stuns scientists Interesting Engineering