A solar flare is a sudden, intense flash of light observed on the surface of the Sun. Usually they are very bright and produce wavelengths of light from across the electromagnetic spectrum. On average a solar flare produces 1 x 1020J of energy. The upper end of the amount of energy emitted can go up to 1 x 1025J which is approximately equal to 1 billion megatons of TNT. As well as light, a solar flare can also emit electrons, ions and other forms of matter. They typically occur when electrons interact with the plasma. Magnetic reconnection causes the particles to accelerate at huge speeds. Radiation emitted from a solar flare takes between one and two days to reach Earth. The radiation emitted by a solar flare as well as any other radiation in space can be very harmful to people that are not within Earth’s atmosphere; In other words, astronauts. The reason for this is that it contains a high amount of energy and is able to penetrate human skin with ease. The energy can then be deposited into and damage cells. A lot of research is conducted into protecting astronauts from space radiation. Although no shielding apart from Earth’s atmosphere could protect a person from radiation emitted by a solar flare, general space radiation can be minimised.
Earth is protected by a “bubble” known as the magnetosphere, which repels most of the radiation and matter that is headed towards Earth. Any remaining radiation that makes it through is just absorbed by the atmosphere. Since the International Space Station is in a low Earth orbit, that too is protected by the magnetosphere. Although risky, the real danger is faced by astronauts traveling much further away.