|a sudden severe disturbance of the earth's magnetic field, caused by emission of charged particles from the sun|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
A disturbance or fluctuation in the Earth's outer magnetosphere, usually caused by streams of charged particles (plasma) given off by solar flares. The entry of large amounts of plasma into the upper atmosphere results in intense auroral displays and other magnetic phenomena in the polar regions of the Earth. See also aurora.