An ancient solar storm left clues in tree rings and a famous poet's diary: 'Red lights in the northern sky'
Space.com ·
The solar cycle was several years shorter and the sun was experiencing an unusually active phase at the beginning of the 13th century — at least, that's the story told by evidence left behind in tree …
The solar cycle was several years shorter and the sun was experiencing an unusually active phase at the beginning of the 13th century — at least, that's the story told by evidence left behind in tree rings and historical records that suggest a burst of protons and enhanced coronal mass ejections battered Earth between the years 1200 and 1204 CE. …
Original source: Space.com