SEEING

Seeing, or more accurately, astronomical seeing, is a measurement of the visual distortion of an celestial object caused by atmospheric effects. The more disturbed the atmosphere, the more distorted the object will appear. Poor ‘seeing’ is one of the primary reasons astronomers place telescopes on mountain tops, or even better, in orbit above the atmosphere. Recently, adaptive and active optics have been developed to compensate for astronomical seeing and improve ground based imagery.