
Update, Wednesday (Jan. 21) at 11 a.m. ET: Geomagnetic conditions are starting to settle, but auroras are still highly likely in the northern tier of the United States tonight, according to NOAA's latest forecasts. Strong (G3-level) geomagnetic storms remain possible overnight, so be sure to check the skies after dark.
A "severe" and record-breaking geomagnetic storm rocked Earth's magnetic shield last night, shortly after the sun unleashed a powerful X-class solar flare. The epic event, triggered by a stream of superfast solar particles, painted widespread auroras at unusually low latitudes across the Northern Hemisphere, particularly in Europe.