A solar flare is a violent explosion in the Sun’s atmosphere with an energy equivalent to tens of millions of hydrogen bombs. Solar flares take place in the solar corona and chromosphere, heating the gas to tens of millions of kelvins and accelerating electrons, protons and heavier ions to near the speed of light. They produce electromagnetic radiation across the spectrum at all wavelengths from long-wave radio signals to the shortest wavelength gamma rays. Solar flare emissions are a danger to orbiting satellites, manned space missions, communications systems, and power grid systems.