Annual growth rings inside the ancient remains of Scots pine trees in the Southern French Alps have revealed evidence of the largest-known solar storm, one that might have fried satellites and knocked out electricity grids had it occurred today.
Researchers said on Monday the solar storm—the sun sending a large burst of energetic particles into space—occurred 14,300 years ago. Evidence for it manifested as a huge spike in radiocarbon—an isotope, or form, of the element carbon—detected in the growth rings of the tree remains along the Drouzet River near the town of Gap.
