A solar flare, visible at the right of the image, occurs when magnetic field lines split apart and reconnect. When the flare is accompanied by a coronal mass ejection, and the magnetic field of the particles in the flare is anti-aligned with the magnetic field of Earth, a geomagnetic storm can occur, with grave potential for a natural disaster. (Credit: NASA/Solar Dynamics Observatory)

A giant solar flare is inevitable, and humanity is completely unprepared

For the past 150+ years, the big ones have all missed us. At some point, our good luck will run out.

From the 1600s through the mid-1800s, solar astronomy was a very simple science. If you wanted to study the sun, you simply looked at the light from it. You could pass that light through a prism, breaking it up into its component wavelengths: from ultraviolet through the various colors of the visible light spectrum all the way into the infrared. You could view the sun’s disk directly, either by putting a solar filter over your telescope’s eyepiece or by creating a projected image of the sun, both of which will reveal any sunspots. Or you could view the sun’s corona during the most visually appealing spectacle that nature has to offer: a total solar eclipse. For over 250 years, that was it.

That changed dramatically in 1859, when solar astronomer Richard Carrington was tracking a particularly large, irregular sunspot. All of a sudden, a “white light flare” was observed…