This week, put on your hard hat and steel capped boots: we're journeying to the centre of the earth! From the soil at the surface to the magnetic molten iron at the core, we're delving into what's going on inside our planet. Plus in the news - How llamas can help us to combat Covid-19, archaeology on a quad bike, and Einstein is proved right again in a test of extreme gravity... Like this podcast? Please help us by supporting the Naked Scientists