Giant sunspot that triggered recent solar 'superstorm' shot out nearly 1,000 flares and a secret X-rated explosion, record-breaking study reveals

Solar Minimum Sunspot During the past 24 hours, sunspot AR2715 has almost quadrupled in size, growing two dark cores larger than Earth. The active region is now crackling with low-level solar flares such as this C2-class explosion recorded by NASA's Solar Dynamics Observatory at 01:15 UT on June 21st. A pulse of extreme ultraviolet radiation from the flare briefly ionized the top of Earth's atmosphere above the Pacific Ocean (map), causing a shortwave radio brownout at frequencies below 10 MHz.