Thursday, February 26, 2015
THE SUN GOD
Despite its bouts of lethal radiation that it flings toward Earth on a regular basis, the surface of the sun is undeniably beautiful. Like Earth, the sun has a magnetic field, but while Earth's magnetic field is hard at work shielding us from most of the sun's harmful radiation, the sun's magnetic field is busy trying to kill us.
Solar flares, like the one below, are the largest explosions in the solar system, releasing ten million times more energy than a volcanic eruption on Earth. They occur when energy builds up within a localized spot on the sun's surface. As that energy eventually grows strong enough, it ejects a tremendous plume of plasma — extremely hot gas — into the sun's upper atmosphere, called the corona.
The energy that produces solar flares comes from the sun's powerful magnetic field. Although the field hangs like a canopy around the sun, the field itself is invisible. But we can see how it affects the gas, like in the example below.
This arch of scorching-hot gas is following the magnetic field lines around the sun, just like howiron filings trace the invisible magnetic field from a bar magnet.