2001 March 1
Astronomers recently witnessed an astounding, large scale solar event
as the Sun's north and south magnetic poles changed places!
But, this complete
solar magnetic field flip
was actually anticipated.
It occurs every 11 years during the
maximum
of the solar activity cycle.
Plagues of sun spots, flaring
active regions, and huge
prominences
are also hard-to-miss signs that the solar maximum is here.
On February 12, the sungazing
SOHO spacecraft captured this
dramatic
image of a magnificent prominence above the Sun's limb.
Seen at the lower right, streams of relatively cool dense
plasma
were lofted along looping magnetic field lines extending outward
about 30 times the diameter of planet Earth.
Far above the limb at the upper right, a disconnected
ghostly arc surrounds a dark cavity with bright central emission.
These features are telltale signs of a
coronal mass ejection --
yet another violent expulsion
of material from the active Sun.
Enormous, intensely bright active regions also mottle the
solar surface
in this image, recorded in the light of energetic
Helium atoms by SOHO's
Extreme
ultraviolet Imaging Telescope.