MEGA-FILAMENT: A magnetic filament snaking around the sun's SE limb just keeps getting longer. The portion visible today stretches more than 700,000 km, a full solar radius.
NASA's STEREO-B spacecraft, stationed over the sun's eastern horizon, saw this filament coming last week. So far the massive structure has hovered quietly above the stellar surface, but now it is showing signs of instability. Long filaments like this one have been known to collapse with explosive results when they hit the stellar surface below. Stay tuned for action.
UPDATE! The "mega-filament" described above has just erupted. NASA's Solar Dynamics Observatory made a must-see movie of the epic blast;
The eruption does not appear to be geoeffective; Earth-effects might be limited to pretty pictures;