A recent study has shed light on a massive sunspot that caused Earth’s largest geomagnetic storm in over 20 years. This sunspot unleashed nearly 1,000 solar flares in just over three months, marking a significant event in our solar system.
In April 2024, astronomers discovered an active region on the sun, known as AR 13664. By May, it grew enormous—about 15 times wider than Earth! This giant sunspot released powerful X-class solar flares, which triggered coronal mass ejections (CMEs) that impacted Earth’s magnetic field multiple times.
Between May 10 and May 13, 2024, a G5-level geomagnetic storm hit Earth—its strength classified as “extreme.” This storm was the most powerful since 2003 and created stunning auroras visible across the globe.
What makes AR 13664 special is its ability to endure several solar cycles. Unlike most sunspots, which vanish after about two weeks, AR 13664 was visible for nearly 94 days. With help from NASA’s Solar Orbiter, researchers tracked it as it rotated out of sight.
According to Ioannis Kontogiannis, a solar physicist at ETH Zurich, “This is the longest continuous series of images ever created for a single active region.” The study released on December 5, 2024, documented 969 solar flares from AR 13664, including 38 that were powerful enough to impact Earth. Most of the largest flares, however, were directed away from us, which minimized further geomagnetic storms.
The most significant flare was an estimated X16.5 magnitude blast, occurring on the sun’s far side on May 20, 2024. Although researchers couldn’t confirm it as the record-breaking flare, its potential strength is noteworthy. For context, an X9 flare earlier that year was considered the strongest in eight years.
Recent data highlights that we might have just passed the peak of the solar maximum, which many scientists expected to occur later. This phase has featured a surge in sunspots and solar storms. Specifically, 2024 has experienced a record number of X-class flares and a significant spike in visible sunspots over the past 23 years.
Understanding these solar events is crucial. They can affect satellites in orbit and various terrestrial technologies. Kontogiannis emphasizes the importance of observing the sun: “We live with this star, so it’s really important we observe it and try to understand how it works and how it affects our environment.” The insights gleaned from AR 13664 help scientists make better future predictions about solar activity.
For ongoing updates on solar activities and their effects, you can visit the [NASA Solar Dynamics Observatory](https://sdo.gsfc.nasa.gov/) for reliable resources.
