Largest solar flare of 2025 blasts Earth
In this DML Report…
On November 11, 2025, the sun emitted an X5.1-class solar flare from sunspot AR4274, marking the largest such event of the year. This flare, classified in the strongest X category, occurred around 5am ET and triggered a radio blackout across Europe and Africa, affecting aviation, maritime operations, emergency services, GPS systems, radar, and satellite communications. NOAA scientists are monitoring for a potential coronal mass ejection (CME) associated with the flare, which could arrive starting Tuesday and lead to a G3-level geomagnetic storm overnight into Wednesday. Additionally, a separate CME from a November 10 flare may impact Earth from the evening of November 11 into November 12.
This X5.1 flare follows two recent events from the same sunspot: an X1.7 on November 9 and an X1.2 on November 10. Since 1942, only 75 X-class flares have been recorded, making them uncommon, according to space scientist Steph Yardley, who noted the flare's high-energy particles were detectable by ground-based instruments. Solar activity remains elevated as AR4274 continues to face Earth and exhibits instability, while another sunspot, AR4276, may produce smaller flares with limited effects.
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Potential impacts from the CME include disturbances to Earth's magnetic field, enabling auroras visible as far south as Pennsylvania, Iowa, and Oregon. Power grids, GPS navigation, high-frequency radio, and satellites in low-Earth orbit could experience disruptions, particularly over polar regions. High-energy particles have prompted radiation alerts, increasing exposure risks for passengers and crew on high-altitude polar flights. There is a 75% chance of additional M-class flares causing brief radio blackouts and minor geomagnetic storms, and a 40% chance of another X-class flare leading to widespread communications interference and potential power grid strain.