Suspended by magnetic fields above a solar active region this dark filament stretches over 40 earth-diameters. The ominous structure captured on May 18 2010 by the Solar Dynamics Observatory shows how near the Sun's edge solar filaments are unstable and often erupt. While the cooler plasma of the filament looks dark, hotter, brighter plasma below traces magnetic field lines emerging from the active region. The filaments actually look bright against the dark background of space and are called prominences. Credit: NASA /Goddard /SDO AIA Team. Buy this as a superb wall poster, a canvas print or a framed print.