THE BIGGEST SOLAR FLARE OF THE CURRENT SOLAR CYCLE: Earth-orbiting satellites have just detected the most intense solar flare of the current solar cycle (so far)–an X8.7-category blast from giant sunspot AR3664. Extreme ultraviolet radiation from the flare ionized the top of Earth’s atmosphere and caused a deep shortwave blackout over the Americas. Full story @ Spaceweather.com.

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Above: Today’s X8.7-class solar flare photographed by NASA’s Solar Dynamics Observatory