The sun is a harsh mistress. Sure, it provides the light and heat that we need to survive, but it’s also capable of wiping us all out at a moment’s notice. Every so often, the surface of the sun experiences what’s called a “solar storm,” sending a burst of highly-charged particles out into the ether. Mild ones we see as lovely light shows in the upper atmosphere. Strong ones? Well, the last one that we had was in 1859, and it was so powerful that it set fire to telegraph lines. Just imagine the devastation that something like that could wreak on our modern power and telecommunications infrastructure. It would drive the world into a new Dark Age.