My wife and our two kids were driving close to Fermi II nuclear power plant in Michigan. We took three digital photos of the power plant. This photo was taken from across Swan Creek. The other two photos show a clear blue sky above the power plant. One picture was taken only seconds before this one and showed nothing unusual. I have no idea what it is. We saw nothing unusual when we took the photo. We've taken over 1,000 photos with this camera and nothing ever looked like this.