On September 1, 1859, the Sun experienced an unusually large storm that ejected a massive cloud of charged particles. Seventeen hours later, on September 2, the cloud collided with Earth’s atmosphere, generating one of the most spectacular displays of the aurora borealis ever recorded. Even people in Hawaii and Cuba witnessed the aurora! So much electromagnetic energy coursed through the Earth that telegraph operators across the Atlantic Ocean could operate their equipment without connecting it to any batteries. Estimates of damage caused by such an event today range upwards of $2 trillion just for the United States. Yet, these remarkable events highlight another way that Earth seems designed for us to live here.