VAN GOGH CLOUDS

On Christmas morning, Gene Hart of Jonesport, Maine, woke up early to enjoy the sunrise before opening presents. What he saw may have been the best gift of all. "There was a cloud formation showing a remarkable series of wave shapes," says Hart. "They were backlit by the rising sun over Moosabec Reach." He snapped this picture of the harbor using a 14-megapixel digital camera:
[link to www.spaceweather.com]
"I also took some 28x zoom images of the wave structure," says Hart. The close-ups are a must-see.

These clouds, sometimes called "billow clouds," are produced by the Kelvin-Helmholtz instability when horizontal layers of air brush by one another at different velocities. A better name might be van Gogh clouds: It is widely believed that these waves in the sky inspired the swirls in van Gogh's masterpiece The Starry Night.