As the Sun approaches the peak of its 11-year solar cycle, a series of powerful solar flares has erupted from its surface, prompting officials to issue a severe geomagnetic storm watch. The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center has forecasted a “severe solar storm” that is expected to hit Earth tonight, marking the first time such an alert has been issued since January 2005.
Geomagnetic storms occur when solar flares and coronal mass ejections (CMEs) erupt from the Sun, causing variations in the solar wind that bombards Earth’s magnetosphere, the protective sheath of our planet’s magnetic field. While these storms can create breathtaking auroras as charged particles from the Sun collide with Earth’s atmosphere along its magnetic poles, they also have the potential to wreak havoc on our technological infrastructure.
The impending storm has been given a Severe (G4) rating by the Space Weather Prediction Center, and experts anticipate at least five CMEs to be directed at Earth between midday today, May 10, and Sunday, May 12. The Sun has been particularly active this week, producing a strong X1.1 flare on Thursday and an even more intense X2.2 flare earlier in the day.
As the world braces for the impact of this severe geomagnetic storm, it’s important to understand the potential consequences. At worst, these storms can disrupt Earth-based navigation systems like GPS and trigger disruptions to infrastructure such as the power grid, radio, and satellite communications. The last G5 geomagnetic storm, which occurred in October 2003, caused power outages in Scandinavia and damaged infrastructure as far south as South Africa.
The ongoing solar cycle, which began in December 2019, has already seen three Severe geomagnetic storms, with the most recent occurring in March 2024. As the cycle progresses towards its peak in 2030, we can expect to see more of these intense solar events. Satellite operators, in particular, are keeping a close eye on the Sun’s activity, as their off-Earth infrastructure is especially vulnerable to solar fluctuations.
While the world awaits updates from NOAA’s Space Weather Prediction Center, many are hoping that the impending storm will bring stunning auroras without the chaos that can accompany such events. For those with a keen eye and a pair of safe eclipse glasses, the large sunspot cluster associated with the recent flares—a whopping 16 times as wide as Earth—can be observed directly.
