VIDEO: Black explosion on the Sun

The second of today's flares (which occurred at 07:00 UT) tore apart and scattered a cloud of neutral hydrogen in the corona. Hydrogen in this state is virtually opaque to the radiation emitted by the Sun's hot atmosphere—the corresponding photons are expended on ionizing the hydrogen and are completely lost in this layer. As a result, a black blanket appears to be cast over the bright surface of the Sun, which persists until the neutral hydrogen is completely ionized or escapes the solar disk. In this case, the latter occurred.