The two most noteworthy features on the sun this week were a pair of elongated filaments (Sept. 8, 2016). The central one was twisted into the shape of an elaborate arch at the center of the sun (yellow arrows). If this were straightened out, it would extend just about across the entire sun, almost a million miles (1.6 million Km). The other, smaller filament, (white arrows) if made straight, might reach about half that distance. Still, pretty impressive. Filaments are elongated strands of plasma suspended above the sun by magnetic forces. They are notoriously unstable and often break apart within a few days. The image was made by combining three images in different wavelengths of extreme ultraviolet light
SDO is managed by NASA's Goddard Space Flight Center, Greenbelt, Maryland, for NASA's Science Mission Directorate, Washington. Its Atmosphere Imaging Assembly was built by the Lockheed Martin Solar Astrophysics Laboratory (LMSAL), Palo Alto, California.