The Mystery Clouds are back over both poles - awesome photo [View all]

Apparently these clouds are in existence only in relation to the sun and its position over the Artic and Antartica horizon. They are at quite a height in the stratosphere, as well

They could be created by the reflective matter coming from man-made pollution, volcanic debris, and what not.

Full discussion here:

http://www.gizmodo.com.au/2012/06/mysterious-electric-blue-clouds-appear-again-over-the-poles/