All mysteries
Mystery #4Tier 3a star on earth

Could we build a tiny star on Earth to power the whole world cleanly?

The Sun has been pouring out light and warmth for billions of years, and it never burns a scrap of coal or oil. It runs on a trick played with the tiny centres of atoms. Imagine bottling that same trick in a machine on Earth: clean power, almost limitless. Could we really build our own little star?

The inside of a fusion machine, a gleaming metal doughnut lined with thousands of tiles, built to hold gas hotter than the heart of the Sun
Photo: Mike Garrett · CC BY 3.0 · via Wikimedia Commons

Your guess

The Sun makes colossal energy without any fuel we would recognise. How do you think it does it, and could we copy that down here on Earth?

There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.

Make a guess to unlock the hints and the answer.