The biggest solar flare in four years erupted from the sun on Tuesday and is heading towards Earth in an event that could disrupt power grids and satellites.
The flare's climax was on Tuesday, creating a massive cloud that covered almost half the sun, NASA said.
A solar flare is a sudden brightening observed over the sun's surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy. (about a sixth of the total energy output of the Sun each second). The term is also used to refer to similar phenomena in other stars, where the term stellar flare applies.
Below is an amazing photo of the solar flare from Tuesday and photos from various solar activities on other dates.