Sun – Dark Solar Filament Liftoff
The long, dark solar filament that had been visible for many days finally lifted off and broke away into space (September 2, 2014). Filaments are elongated clouds of plasma tethered above the Sun’s surface by powerful magnetic forces. Filaments are notoriously unstable.
They appear darker when viewed in extreme ultraviolet light because they are somewhat cooler than the underlying material. The video covers about 14 hours of activity.