News · 15 July 2026
Earth's inner core grows 1mm yearly, keeping magnetic field alive
Photo by Javier Miranda on Unsplash
Our planet's inner core grows by about a millimetre each year as molten iron freezes onto it, which powers Earth's magnetic field. A September 2025 study found dissolved carbon allows iron to freeze at the core's conditions, meaning it wouldn't exist without it. Slow growth releases energy, stirring the outer core to create the field that protects our atmosphere.
Reported by Space Daily · How we write briefs