Solar flare, illustration. This flare, or prominence, is erupting from the chromosphere, which lies above the Sun's visible surface. Prominences are dense clouds of plasma, or ionised gas, in the Sun's outer layer, the corona. Upon erupting, the flares become part of the solar wind. They may be associated with strong magnetic activity inside the Sun, and some flares are powerful enough that, on reaching Earth, they can disrupt telecommunications and satellite systems. Solar flares can extend hundreds of thousands of kilometres into space.