Explanation:
Why is the corona of the
Sun so hot?
Extending above the
photosphere or visible surface of
the Sun, the faint, tenuous solar corona can't be easily seen from Earth, but it is
measured to be hundreds of times hotter than the
photosphere itself.
Astronomers have long
sought the source of the corona's heat in
magnetic
fields which loft monstrous loops of
solarplasma above the photosphere.
Detailed observations
of
coronal loops from the orbiting
TRACE satellite are
pointing more closely to the unidentified energy source.
Recorded in extreme ultraviolet light,
this and other TRACE images indicate that
significant heating occurs low in the
corona, near the bases of the loops as they emerge from and return to the
solar surface.
This tantalizing
TRACE image shows
clusters of the majestic, hot
coronal loops which span 30 or more
times the diameter of planet Earth.
