Explanation:
North America
at night is easy to recognize in
this
view of our fair planet from orbit, acquired
by the Suomi-NPP satellite on October 8.
The spectacular waves of visible light emission rolling
above the Canadian provinces of Quebec and Ontario
in the upper half of the frame are the Aurora Borealis or
northern lights.
Encircling the poles and extending to lower latitudes,
impressive aurorae seen
during the past few days
are due to strong geomagnetic storms.
The storms were triggered
by a solar coronal mass
ejection on October 4/5, impacting
Earth's
magnetosphere some three days later.
The curtains of light, shining well over 100 kilometers
above the surface, are formed as charged particles
accelerated in the magnetosphere excite oxygen and nitrogen
in the upper atmosphere.
