I always love the pictures posted on Astronomy Picture Of the Day. And these clouds are particularly interesting. Apparently no one knows for sure how they are formed, but every year they appear over parts of Australia.
You know, when it really boils down to it, the whole reason I'm in science and engineering is to better admire the beauty of Creation. If it weren't for the engineers who designed the airplane, this unique view of these unique clouds would not have been possible.