AR 3664 on a Setting Sun
It was larger than the Earth

A distant Sun is seen over water and between foreground
trees. On the lower part of the Sun is the gigantic
active region AR 3664 visible by its dark sunspots.
Please see the explanation for more detailed information.
It was larger than the Earth.

It was so big you could actually see it on the Sun’s surface without magnification.

It contained powerful and
tangled magnetic fields
as well as numerous
dark sunspots.

AR 3664, it developed into one of the most energetic areas seen on the
Sun in recent years,
unleashing a series of explosions that led to a
surge of energetic particles striking the Earth, which created
beautiful auroras.

And might continue.

active regions
on the Sun like AR 3664 can be quite dangerous,
this region’s
Coronal Mass Ejections
have not done, as yet, much
damage to Earth-orbiting satellites or Earth-surface electrical grids.

the enormous active region was captured on the
setting Sun a few days ago from

The composite image
includes a very short exposure taken of just the
Sun’s surface, but mimics what was actually visible.

AR 3664 is
now rotating away from the Earth,
although the region may survive long enough to come around again.


AR 3664 on a Setting Sun