A Solar Filament Erupts
What's happened to our Sun?
Nothing very unusual -- it just
threw a filament.
Toward the middle of 2012, a long standing
solar filament
suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).
The filament had been held up for days by the Sun's ever changing
magnetic field
and the timing of the eruption was unexpected.
Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting
explosion
shot electrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's
magnetosphere, causing visible
aurorae.
Loops of plasma surrounding an
active region can be seen above the erupting filament in
the ultraviolet image.
Over the past week the number of sunspots visible on the Sun unexpectedly
dropped to zero, causing speculation that
the Sun
has now passed a very
unusual solar maximum,
the time in the
Sun's 11-year cycle
when it is most active.