Solar flare threatening Earth. Computer artwork of the Earth being threatened by a solar flare (yellow). A solar flare is an explosion in the Sun's atmosphere that causes a large increase in levels of dangerous radiation and charged particles. If the flare hits Earth, some of the charged particles will be diverted by the Earth's magnetic field, but neutral particles, high-energy particles, and radiation can penetrate to the surface. Radiation levels in space can be lethal, and raised radiation levels at the surface can damage genetic material, causing mutations. Solar flares also severely disrupt satellite and radio communications. The coloured lights are aurorae.