April 01, 2008
Two sundogs filled the skies over northern Texas on this curious spring day; one looked like it could bark. The meteorological sundog or parhelion at left is neither a sleight of hand nor an April Fools' Day joke. These colorful spots, which occur about 22 degrees from either side of the Sun, are formed by light interacting with ice crystals in cirrus type clouds. Sundogs may become visible when hexagonal, plate-shaped ice crystals, which are aligned with their flat faces horizontal, refract sunlight. The pooch at lower right seems to take a liking to the Sun's familiar and faithful companion. Arf!