The Sun is stronger than our electric grid — and we are defenseless against it

Imagine being a telegraph operator in September 1859. You’re sitting at your station, using cutting-edge technology to tap out messages hundreds and thousands of miles away. Suddenly, brilliant auroras light up the night sky from the tropics to the poles.

Then chaos.

Sparks shower from your equipment, shocking you with a jolt strong enough to knock you out of your chair, while igniting your telegraph message papers. You later find out that some of your fellow operators could still...