Scientists have long known that the Earth’s inner core is a hot, dense ball of metal, surrounded by an outer core of molten iron. But new research reveals that this inner core is not only spinning in a different direction, but also changing shape.

For decades, researchers have suspected the inner core might deform over time. A new study published in Nature Geoscience now supports this theory, with scientists analyzing seismic waves from powerful earthquakes.

The seismic waves show that the outermost layer of the inner core may be more flexible than the deeper layers. Riskin says tracking these changes could save our lives, as the inner core’s movement plays a crucial role in generating the Earth’s magnetic field, which shields us from harmful solar radiation. That’s why Sun’s radiation turns into northern lights and does not kill us, Riskin explains.

“Mars doesn’t have that. It used to have an atmosphere, and this solar wind just ripped the atmosphere off and blew it into space,” Raskin said. “That would happen to us if our core is not doing its job properly.”