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.