Scientists have discovered a new core at the center of the Earth

Back in my day, there were only four layers of Earth: the crust, mantle, liquid outer core and solid inner core. Now, scientists have revealed a new, distinct layer within our planet’s inner core, which could help inform the evolution of Earth’s magnetic field.

In a study released this week, a pair of seismologists at the Australian National University documented new evidence of a 400-mile-thick solid metallic ball at the center of Earth’s inner core — like the smallest figurine of a massive, planetary Russian nesting doll set. The new layer consists of an iron-nickel alloy, like other parts of the core. But it has a different crystal structure that causes shock waves from earthquakes to reverberate through the layer at different speeds than the surrounding core, the study found.