Red Auroral Corona
Credit & Copyright:
Duane Clausen
Few auroras show this level of detail.
This unusual display of an
auroral corona occurred on
Earth three days
after an unusual solar event -- the fifth
most powerful explosion yet recorded on the
Sun.
An X14-class solar flare on April 15 sent a tremendous
Coronal Mass Ejection (CME) into the Solar System.
This CME did not directly impact the
Earth.
The Solar-System wide shock wave it created probably did,
however, causing a
G3-class geomagnetic storm and a night filled with
colorful auroras across much of northern
North America.
The unusual red color of this
Michigan aurora is
caused by solar ions striking
oxygen molecules 300 kilometers high in
Earth's atmosphere.
More typical green auroras are
caused by oxygen recombining only 100 kilometers high.