Viv sent me some photographs of the sun taken
from Tabuk in northwest Saudi Arabia that appear to show some solar flares. A
solar flare occurs when magnetic energy that has built up in the solar atmosphere
is suddenly released causing a sudden, rapid, and intense variation in
brightness. As the magnetic energy is being released, particles, including
electrons, protons, and heavy nuclei, are heated and accelerated in the solar
atmosphere. This energy release is ten million times greater than the energy
released from a volcanic explosion but is less than one-tenth of the total
energy emitted by the Sun every second. Solar flares extend out to the layer of
the Sun called the corona. The corona is the outermost atmosphere of the Sun,
consisting of highly rarefied gas. This gas normally has a temperature of a few
million degrees Kelvin. Inside a flare, the temperature typically reaches 10 or
20 million degrees Kelvin, and can be as high as 100 million degrees Kelvin.