February 22, 2010
NASA spacecraft and amateur astronomers alike are monitoring a staggeringly-long filament of magnetism on the sun. It stretches more than a million kilometers around the sun's southeastern limb
As this movie shows, the filament has remained mostly stable for at least two days. However, similar filaments in the past have been known to collapse, and when they hit the surface of the sun--bang! A tremendous explosion called a "Hyder flare" results, sometimes rivaling the strongest flares produced by sunspots. Solar physicists have not yet learned to predict Hyder flares, so we cannot estimate the odds of one now. Readers with solar telescopes are encouraged to monitor developments.