THE STRONGEST FLARE OF SOLAR CYCLE 25: Sunspot AR3842 erupted again on Oct. 3rd producing the strongest solar flare of the current Solar Cycle so far. NASA's Solar Dynamics Observatory recorded the X9.0 blast. A halo CME is emerging in SOHO LASCO C3 imagery. The previous X7 and now X9 CMEs combined could spark strong geomagnetic storms. Stay tuned for updates… | Solar Underground

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.