Palomar Observatory Sky Survey (POSS)

The Palomar Observatory Sky Survey (POSS) is a photographic survey of the sky from the north celestial pole to Dec. -30°, carried out using the 1.2-meter Schmidt telescope at Palomar Observatory and financed by the National Geographic Society. The original survey, completed in 1958, involved of 936 pairs of plates 0.355 meters square with a field of view of 6.5°, each consisting of one plate sensitive to red light and one to blue light. A second survey was started in 1985 from the north celestial pole to the equator, using modern plates; when complete, it will consist of 894 fields in blue, red, and infrared light.