Earth’s inner core: nobody knows exactly what it’s made of – now we’ve started to uncover the truth

The iron-rich core at the centre of our planet has been a crucial part of Earth’s evolution. The core not only powers the magnetic field which shields our atmosphere and oceans from solar radiation, it also influences plate tectonics which have continually reshaped the continents.

But despite its importance, many of the most fundamental properties of the core are unknown. We do not know exactly how hot the core is, what it is made of or when it began to freeze. Fortunately, a…

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