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 successively slammed into our planet's magnetic field.
