New Aurora Season / by Michael Johns

The Kp index, a measure of the strength of geomagnetic storms from the sun, spiked last night; jumping from a mild 3 to a strong 7. It turns out the Earth had passed through the wake of a coronal mass ejection, where the sun essentially burps out a giant plasma cloud that travels outward from the source as solar wind. This wake weakened the magnetosphere of our planet, allowing solar wind to spill into the upper atmosphere and take on the form of bright green aurora. Space weather forecasters were not predicting this event, a surprise display of northern lights that kicked off the 2018-19 aurora season.