Every now and then our star produces immense flares of particles and radiation that can wreak havoc on Earth. For more than 150 years scientists studying these outbursts and how they affect our planet have placed great focus on a single, seemingly pinnacle example: the Carrington Event of 1859. An eruption from the sun walloped Earth, pumping enough energy into our planet’s magnetic field to set off a massive geomagnetic storm that created beautiful auroral displays but also sparked electrical fires in telegraph lines. The storm was seen as an odd, minor inconvenience that caused limited damage to the electrical infrastructure of the time. Researchers today, however, recognize the Carrington Event, along with a 1921 storm of comparable strength, as an ominous warning of future catastrophes.