Explanation:
Suspended by
magnetic fields above a solar
active region
this dark filament stretches over 40
earth-diameters.
The ominous structure appears to be frozen in time
near
the Sun's edge, but solar filaments are unstable and often erupt.
The detailed scene was captured on May 18 in
extreme ultraviolet
light by cameras on board the
Solar
Dynamics Observatory.
While the cooler plasma of the
filament
looks dark,
hotter, brighter plasma
below traces magnetic field lines emerging from the active region.
When seen arcing above the edge of the Sun,
filaments actually look bright against the dark background of space and
are called prominences.
