CNN reports:

Forecasters knew something unusual was hurtling toward Earth. Three days before a solar storm arrived on May 10, 2024, they watched as a dark knot on the sun — tangled magnetic field lines spanning 124,000 miles — took aim at the planet.

“That’s magnets twisting and turning and popping through each other,” said Shawn Dahl, service coordinator at the Space Weather Prediction Center operated by the National Oceanic and Atmospheric Administration in Boulder, Colorado. “Think about a rubber band, twisting it and bending it and stretching it. It’s going to break.”

When a sunspot snaps its magnetic rubber bands, it can send extra bursts of energy and plasma toward us. These solar storms sometimes harm electric grids and radio communications. The May 2024 incident — known as the Gannon storm — recalled memories of the Carrington Event more than 150 years ago. Considered one of the most intense solar storms in human history, the September 1859 episode disrupted telegraph systems worldwide.

Gannon was three times less intense, but still the first severe solar storm to test our modern realm of satellites, electric grids and digital technology. Its impression felt like a bullet dodged. While the four-day storm stopped short of creating power outages in North America, farmers in at least 12 states had to stop planting their crops because of damage to precision GPS sensors. That alone resulted in $500 million to $1 billion in economic losses.

New research offers a map of what would happen if the next storm took a more powerful turn. The study, published Friday in AGU Advances, depicts the most advanced picture yet of how a rare but massive solar storm could affect some US industries and electric systems more than others. [Continue reading…]