Overview
- The U.S. Space Weather Prediction Center said a major geomagnetic storm struck Monday at 20:38 Paris time and reached level G4 on the five-step scale.
- Auroras were seen at unusually low latitudes, from Brittany and the French Alps to the United States as far south as Alabama, as well as parts of China and Canada.
- Officials warned of possible degradation of high‑frequency communications, satellite disruptions, and power‑grid overloads, with elevated radiation risk for astronauts and some flights.
- Scientists link the display to a powerful solar eruption 24–48 hours earlier near solar maximum, noting that aurora colors vary by altitude and atmospheric composition.
- By January 21, activity had weakened as expected, widespread sightings were documented, and agencies continued monitoring without reports of major confirmed infrastructure failures.