Aurora Borealis in a view from space. Colorful auroras spread across Canada and some northern US states Friday night when the interplanetary magnetic field (IMF) near Earth unexpectedly tilted south, sparking a geomagnetic storm.
BLUE AURORAS: Northern Lights are usually green, and sometimes red. Those are the colors produced by oxygen when it is excited by electrons raining down from space. Micha Bäuml of Straumfjord, Norway, witnessed an appariton of aurora-blue.
Coronal Mass Ejection Causes Colorful Aurora. An aurora in Whitehorse, Yukon, Canada, that appeared in the sky in the early hours of Oct. 2012 due to the effects of a coronal mass ejection (CME) that erupted from the sun three days earlier.