An alien world with a seemingly sulphur-filled atmosphere may be the most volcanic planet astronomers have ever spotted.

We have never directly detected volcanic activity outside our solar system, in part because current telescopes aren’t powerful enough to take images of exoplanets’ surfaces. We might be able to spot alien volcanoes by measuring the gases they pump into a planet’s atmosphere, but this is also at the very limit of what current telescopes can do – there have been tantalising hints of atmospheres on rocky…