Two Eruptive Solar Prominences

The STEREO Behind spacecraft was treated to the sight of not one but two eruptive prominences (Nov. 17-18, 2009). Located near the seven and ten o'clock positions, the prominences, as seen here in extreme UV light, erupted almost sequentially within a few hours of each other. Although it is hard to see from this perspective, the second prominence (as observed by the SOHO spacecraft) extended upwards at least 18 times the size of Earth. Prominences are cooler clouds of gases suspended above the Sun by magnetic forces and known to be relatively unstable.

• twoprom_zm_best.mov   
• twoprom_zm_4.mov   
• twoprom_zm.mpg   
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