NASA - Profiling the Largest Solar Explosions

Solar flares – they're big and they're fast. They can knock out a satellite or create a beautiful aurora. And the jury is still out on what causes these explosions. Flares, and the related coronal mass ejection, shoot energy, radiation, and magnetic fields out into space that can harm satellites or humans in space. Current observations aren't precise enough to determine whether the eruptions are driven by energy surging through the sun's surface, or by the sudden release of energy that has slowly accumulated in the atmosphere. This aurora over Valkeakoski, Finland on September 15, 2000 resulted from the September 12 coronal mass ejection featured in the video above. Credit: Tom Eklund Now, a new way of looking at old data has changed all that, but the results have created more mystery: There isn't enough energy passing through the surface during the eruption to drive the explosion.