FROM THE EDITOR
Earth’s core is a scary place, when you think about it. If you travelled straight down for around 2,900km (1,802 miles) – that’s roughly equivalent to travelling from London to Edinburgh four or five times over – you’d reach it. Specifically, you’d have dug through Earth’s mantle to reach the outer core. Here, rock gives way to liquid metals and the temperature soars to nearly 2,700°C (5,000°F). Dig (or swim?) a little deeper, another 2,000km (1,243 miles) or so, and you’ll reach the inner core. Here, temperatures double, rising to over 6,000°C (10,800°F) – as hot as the surface of the Sun. At this temperature almost everything vaporises, even diamonds, but the material here is under enough pressure to keep it liquid.