THE sun is more active now than it has been for a millennium. The realisation, which comes from a reconstruction of sunspots stretching back 1150 years, comes just as the sun has thrown a minor tantrum. Last week, a giant plume of material burst out from our star’s surface and streamed into space, sparking warnings of an impending geomagnetic storm.
The dark patches on the surface of the sun that we call sunspots are a symptom of fierce magnetic activity inside. Ilya Usoskin, a geophysicist who worked with colleagues from the University of Oulu in Finland and the Max Planck…
