In a time when auroras danced over most of the Earth and the sun’s rays were more powerful than today, sunscreen may have been Homo sapiens’ secret weapon

They created vibrations deep in the ground at 110 different locations to uncover the secrets of the supervolcano

Walking in this way could protect you from heart rhythm abnormalities, heart attacks and strokes

A bold new study has found that you could be getting enough protein – but not enough amino acids

Iceland sits upon two continental plates – the Eurasian plate and the North American plate. These huge chunks of Earth’s surface are yawning apart at a pace of 2cm (just shy of 1in) every year. This movement creates fissures in Earth’s surface, like cracks in its shell. In Iceland, the Silfra fissure sits over an aquifer, where glacial meltwater gathers underground, and so this crack became a lake. It's the only body of water in the world that you can dive into and find yourself swimming between two tectonic plates. You can, almost, reach out and touch the Eurasian plate with one hand and the North American plate with the other. I couldn’t tell you why that appeals to me as an idea, as something to see before I die, but it does. While the fissure is around 60m (200ft) deep underwater, in my imagination, swimming through those waters would feel like Earth was opening up beneath me. The idea that there’s another world beneath us has a special kind of hold on humanity, one that’s almost as alluring as the idea that there’s life beyond Earth. The thing is, seismology is now in a place where it’s able to give us a detailed picture of what’s really going on deep inside the planet. And every time it does, our understanding of what it’s like down there changes. In this issue, we share what we've discovered.

Despite centuries of research, one of Earth’s most awe-inspiring phenomena is still not fully understood.

It's easy to get sick of a 24-hour news cycle of war, climate crises and economic turmoil. Here's how a break will help your mental health – and gut

Why carbon-rich asteroids rarely reach the ground may hold the key to our cosmic origin story.

Many adults don’t get enough of a nutrient that could be crucial for preventing cognitive decline

Particles released by decaying satellites could be causing an unwanted, harmful impact to the ozone layer.