A solar flare is an explosion on the Sun that happens when energy stored in
twisted magnetic fields (usually above sunspots) is suddenly released. Flares
produce a burst of radiation across the electromagnetic spectrum, from radio
waves to x-rays and gamma-rays.
Scientists classify solar flares according to their x-ray brightness in the
wavelength range 1 to 8 Angstroms. There are 3 categories: X-class flares are
big; they are major events that can trigger planet-wide radio blackouts and
long-la
