Star trails around north celestial pole
author: Jia Hao/Novapix
reference: a-pas01-00123
Image Size 300 DPI: 25 * 15 cm
Startrail taken from Kalajun Prairie, Xinjiang, China on Jul. 27, 2008.
Star trails are made by the combination of: the spinning of the Earth, the use of a stationary mount or tripod and a long exposure of the film. As the Earth spins, the stars begin to make concentric circles on the photograph. The closer stars are to Polaris, our North pole star, the smaller their circles. Thar farther away they are, the larger their circles.