The biggest solar flare in recorded history, called the Carrington Event, took place in 1859. Back then, this monster solar flare caused telegraph wires to catch on fire over much of Europe and North America. It created atmospheric disturbances all over the planet, with the aurora borealis blanketing the night sky over Cuba, Mexico, Hawaii, Japan, and China. You could read the newspaper at night in the Caribbean by the light of the aurora. In Baltimore the aurora was brighter than a full moon.
