Double-barreled blast

Two active regions glow brightly in this ultraviolet image of the sun, acquired by NASA's STEREO Ahead spacecraft on Feb. 12 and posted online March 20. A small flare rises from the active area on the left. Flares are intense solar explosions that blast radiation into space. This one paints a white line across the left edge of the sun's disk. Meanwhile, the active area on the right churns with magnetic loops