New study reveals that Earth's inner core is undergoing unexpected structural changes, challenging long-held assumptions about its solidity.

Scientists of course cannot cut into Earth and directly observe its insides. Instead, their knowledge is inferred from the vibrations generated by earthquakes that pass through the planet. The speed and the direction of the seismic vibrations change depending on the density and the elasticity of the rocks.

A new study shows that the inner core changed shape in just a few decades, challenging previous assumptions and revealing hidden dynamics deep within Earth.

The planet’s inner core was previously thought of as a hard, solid sphere. But a new study has found that its edges are softer than realized and actually changing shape.