As the STEREO (Behind) spacecraft observed in extreme UV light, the Sun popped off no fewer than six eruptions over just two days (Aug. 14-15, 2010). At one point, three events were occurring at the same time. Most of these were eruptive prominences in which cooler clouds of gases above the surface break away from the Sun. The most powerful of the events, a coronal mass ejection, began around 6:30 UT on Aug. 15. It was harder to see from this spacecraft’s angle since it blasted out from the whiter active region in the lower center, so it had the Sun as its backdrop.
Courtesy of SOHO/STEREO consortium. SOHO is a project of international cooperation between ESA and NASA.