Earth’s Core May Exist in a Superionic State Driving the Planet’s Magnetic Behaviour

Scientists have discovered that Earth’s inner core may exist in a superionic state, where carbon atoms flow like liquid through solid iron. This could explain the core’s softness and reveal a new energy source driving the planet’s magnetic field.

The inner Earth may be far stranger than we imagined. A new study suggests that our planet’s solid inner core is not entirely solid after all, but exists in a rare “superionic state” where atoms behave in a way unlike any familiar material on Earth. This surprising discovery could finally explain the core’s puzzling softness and its role in powering the magnetic field that protects our planet.

A Hidden State of Matter Beneath Our Feet

Deep below the crust and mantle, Earth’s inner core endures pressures over three million times higher than at the surface and temperatures rivaling the Sun. For decades, scientists believed this region was a rigid iron sphere. Yet seismic data has long shown that waves slow down inside the inner core, indicating an unexpected level of softness or fluidity.

The new research, led by scientists at Sichuan University, reveals that this contradiction may be explained by a superionic state a phase where carbon atoms drift freely like liquid through a solid iron lattice. This creates a material that behaves both like a solid and a liquid simultaneously.

How Scientists Recreated the Core on Earth

To test the idea, researchers blasted iron carbon samples with extreme shockwaves, propelling them at nearly 25,000 km/h. These forces produced pressures and temperatures approaching those inside the inner core. As the samples neared these conditions, they became dramatically more malleable, indicating a transition into the superionic phase.

This behaviour aligns with earlier computer models and offers the strongest experimental evidence yet that Earth's inner core is far more dynamic than previously believed.

Implications for Earth’s Magnetic Heartbeat

The study suggests that the flowing carbon atoms inside the superionic core could help transport heat and feed the geodynamo—the mechanism that generates Earth’s magnetic field. This adds a newly recognised energy source to the planet’s magnetic engine, long thought to rely only on convection and thermal changes.

A dynamic, shifting inner core may also influence how Earth cools over time and how the magnetic field fluctuates. The findings could even extend beyond our planet, offering clues to the interiors of rocky exoplanets and how their magnetic fields evolve.

As scientists move away from the idea of a perfectly solid core, this hidden superionic world may reshape our understanding of Earth’s deepest mysteries.