S is for Sun
Taken yesterday from the SOHO spacecraft, this
false-color image shows the active
Sun
near the March
Equinox,
the beginning of
Autumn in the south and Spring in the northern hemisphere.
Recorded in a band of extreme
ultraviolet light emitted
by highly ionized iron
atoms, the Sun's upper atmosphere or
solar corona shines
with an array of active regions and plasma loops suspended
in magnetic fields.
The bright coronal structures and loops seen here
have temperatures of about 1.5 million
kelvins.
By chance, the Sun's earth-facing
side also seems to be
marked with a twisting complex of dark
filament channels
shaped like a giant "S".
Filaments represent relatively (!) cool material in the corona
which show up as prominences when seen at the Sun's edge.
For planet Earth, recent
solar activity has made auroral displays
likely around this year's March Equinox.