The most powerful solar storm in nearly six years slammed Earth today (March 24), but strangely, space weather forecasters didn't see it coming.
The geomagnetic storm peaked as a severe G4 on the 5-grade scale used by the U.S. National Oceanic and Atmospheric Administration (NOAA) to assess the severity of space weather events. The storm's unexpected ferocity not only made auroras visible as far south as New Mexico in the U.S., but it also forced spaceflight company Rocket Lab to delay a launch by 90 minutes.
