James Stewart

Over 3,000 miles below the surface, right at the centre of the Earth, lies a solid spheroid.

Primarily made of iron and nearly as big as the Moon, its temperature rivals that of the Sun.

This is Earth's inner core.

It spins independently at the very heart of our planet.

And while we can't see it for ourselves, its immense heat triggers processes that impact us all.

Plate tectonics that manifest in some of the most awe-inspiring and deadly sights on the surface.

Our planet's invisible magnetic field, which makes life possible.

It's no wonder that Earth's core has captured the imaginations of generations of scientists who have developed ever more sophisticated instruments to investigate its fiery depths.

And the latest research efforts have yielded discoveries that could have come straight from a Hollywood film.

Our inner core appears to not only have stopped spinning, but has in fact started moving backwards.

Why has this happened?

And what does it mean for us, topside?

I'm James Stewart, and you're watching Astrum Earth.

In order to get to our planet's core, we need to go down.

Call it my version of a journey to the centre of the Earth.

Each layer has its own role in creating, sustaining and sometimes destroying the world above.

And all of them are influenced by the solid iron heart.

Here at the surface, we walk upon the crust, a mere brittle shell.

Though it feels pretty solid to us, it is in fact fractured into giant tectonic plates that drift, collide and grind past each other, causing violent earthquakes and devastating volcanic eruptions.

How it moves is all thanks to the layer below, the mantle.