Giant Sunspot Erupts: Solar Superstorm Flares & X-Ray Explosion Revealed
- A record-breaking study into a giant sunspot that triggered Earth's biggest geomagnetic storm in more than two decades has revealed surprising new details about the explosive dark patch.
- Back in April 2024, astronomers spotted a growing group of sunspots on the solar surface.
- But a recent study has revealed that at least one sunspot, designated AR 13664, was surprisingly resilient.
A record-breaking study into a giant sunspot that triggered Earth’s biggest geomagnetic storm in more than two decades has revealed surprising new details about the explosive dark patch. The monster sunspot unleashed almost 1,000 solar flares in just over three months, and may have discreetly birthed the most powerful outburst of the current solar cycle.
Back in April 2024, astronomers spotted a growing group of sunspots on the solar surface. This new active region (AR), dubbed AR 13664, quickly swelled in size, eventually reaching a diameter 15 times wider than Earth by early May. It then quickly unleashed a barrage of X-class solar flares – the most powerful type of solar explosion – that fired a series of coronal mass ejections (CMEs) toward Earth,which successi“`html
Sunspots are temporary features on the sun’s surface that appear as dark patches, and they’re often the source of powerful solar flares and coronal mass ejections (CMEs). These events can disrupt radio communications, damage satellites, and even trigger geomagnetic storms on Earth, causing dazzling auroras. However, sunspots don’t last forever. They typically emerge, evolve over days or weeks, and then decay.
But a recent study has revealed that at least one sunspot, designated AR 13664, was surprisingly resilient. Researchers observed this sunspot for nearly three and a half solar rotations – about 94 days – and found that it persisted much longer than expected. Sunspots usually disappear after one or two rotations as they are carried across the sun’s visible disk (the hemisphere facing hemisphere for up to two weeks at a time before rotating out of view, but they reappear if they survive the trip across our home star’s far side.)
In a new study published Dec. 5 in the journal Astronomy & Astrophysics, researchers analyzed observations of AR 13664 spanning 94 consecutive days between April 16 and July 18, 2024, which equates to roughly 3.3 trips around the sun.Thanks to images captured by NASA‘s Solar Orbiter, which circles the sun, researchers were able to keep tabs on the sunspot as it rotated out of view.
The event began with at least five successive coronal mass ejections (CMEs) exploding from the sun. These CMEs collided with Earth on May 10-11, 2024, causing a G5-level geomagnetic storm – the highest rating on the National Oceanic and atmospheric Administration’s (NOAA) space weather scale. 
(Image credit: NASA/SOHO)
The flare’s intensity caused widespread disruptions. NOAA’s Space Weather Prediction Centre reported radio blackouts across parts of North and South America.Power grids experienced fluctuations, and satellite operations were temporarily affected. The storm also generated impressive auroral displays visible as far south as florida and Texas.
AR 13664’s activity is a stark reminder of the sun’s power, particularly during solar maximum – the peak of the sun’s roughly 11-year cycle. During this phase,sunspot numbers and solar storms increase significantly. Scientists believe we may have already passed the peak of the current solar cycle, Solar Cycle 25, with a possible peak occurring in late 2023 or early 2024, according to Live Science.
The current solar cycle is proving to be more active than predicted. As of January 12, 2026, NOAA reports 338 sunspots on the sun’s surface, exceeding initial forecasts for this stage of the cycle. This heightened activity suggests the potential for more intense solar flares and geomagnetic storms in the coming years.