Important notice about STEREO Behind
Relentless Active Region
A vigorous active region fired off more than a dozen solar storm events over two days (Jan. 27-28, 2011) and at least two of these events sent waves across much of the Sun. NASA's earth-orbiting Solar Dynamics Observatory spacecraft saw got only an edge-on view of these events, but the STEREO (Ahead) spacecraft, viewing the Sun in extreme UV light, had a front row seat, so to speak. The active region sputtered and fizzled with activity almost the entire time. The largest event was a flare and coronal mass ejection, seen as a flash (seen in the still) followed by a compression wave that raced outward, leaving a dark area behind it.
Last Revised: March 19, 2018 15:00:39 UTC
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