In late summer of 1859, the Sun hurled a cloud of charged particles at Earth so powerful that telegraph wires sparked, operators received shocks, and auroras glowed as far south as the Caribbean.

Scientists have long assumed that there’s an upper limit to the intensity of the solar winds that reach Earth. New research suggests there’s not—and the implications are alarming. Solar storms occur ...

Add Yahoo as a preferred source to see more of our stories on Google. Illustration of solar wind streaming from a fuming Sun drives auroras bright enough to be seen far from the poles, a dazzling ...