AT decorations

This tree across the lake from us was decorated with the most unusual trimming today....it's frozen fog.
I awoke around 3 am and looked out our bedroom window at.......nothing.  
It was eerie because I had been star-watching earlier hoping to see the Northern Lights (which I didn't see :-(( ).
This morning all of the trees were frosted.  I don't know how fog can exist below freezing, but there it was!
When the sun hit the branches, it was dazzling!