Get Ready for Some Major Space Weather

If you like sky shows, the sun is setting one up for this week, while giving satellite operators a mild headache. NASA says four powerful solar flares blasted off the sun in the space of around 20 hours on Sunday and Monday, all in the strongest "X-class" category. Three erupted on Sunday, rated X1.0, X8.1, and X2.8, followed by an X1.6 flare early Monday. There was another strong flare, an X1.5, Tuesday afternoon, according to NOAA's Space Weather Prediction Center. The bursts came from a rapidly growing sunspot cluster now facing Earth, labeled RGN 4366, and are linked to coronal mass ejections—huge clouds of charged particles hurled into space, the BBC reports.

The X8.1 flare was the strongest since October 2024 and one of the 20 strongest in the last 30 years Scientific American reports. In an explainer of the solar flare scale, which classified flares by strength, NASA says some X-class flares, unlike those in the less powerful B, C, and M classes, can be higher than X-9. "The most powerful flare on record was in 2003, during the last solar maximum," NASA says. "It was so powerful that it overloaded the sensors measuring it. They cut out at X17, and the flare was later estimated to be about X45."

• The Space Weather Prediction Center expects elevated space weather through Saturday as that active region continues to rotate across the sun's Earth-facing side. The associated ejections are forecast to reach our planet around Thursday, potentially triggering stronger auroras and a minor geomagnetic storm. Northern lights could be visible in northern parts of the US.

The sun is just past the peak of its 11-year activity cycle, known as Solar Cycle 25, which has already fueled more frequent and intense aurora displays. Along with the visual payoff, strong flares and solar eruptions can disrupt radio communications, GPS, satellites, and power systems, and pose risks to spacecraft and astronauts. Forecasters describe the current geomagnetic storm level as "minor" but expect "moderate to high" activity to continue—and warn that more hefty flares from RGN 4366 are likely in the coming days.