Solar oddity! NASA Sun Science’s Solar Dynamics Observatory came across this oddity, a rarely-observed dark filament that encircles an active region on the Sun, seen from Oct. 29-31. Solar filaments are clouds of charged particles that float above the sun, tethered to it by magnetic forces. They are usually elongated and uneven strands. Only a handful of times before have we seen one shaped like a circle. Learn more: http://go.nasa.gov/2jlN5M3
