At the tumultuous peak of its 11-year activity cycle, the sun is spitting out X-ray flares and belching giant clouds of high-energy particles at a furious rate.
On April 2, the sun unleashed the most powerful flare recorded since regular
measurements began 25 years ago.
Packing more energy than 100 megatons of TNT, the flare erupted from a turbulent
region on the sun's northwest edge that had grown to be 13 times bigger than
Earth's surface. Because the explosive region soon rotated onto the sun's far
side, Earth was spared the brunt of the storm. Nonetheless, ultraviolet and X-ray
radiation from the flare triggered a temporary radio blackout on Earth's sunlit
The flare was more powerful than the infamous one that disrupted power grids in