ARC-1985-A86-7002

Range : 36 million km. ( 22 million miles ) P-29426B/W This Voyager 2 photograph of Uranus shows the is the first picture to show clear evidence of latitudinal banding in the planet's atmosphere. This is a computerized summation of five images shot by the narrow angle camera. The concentric pattern emanates like a bulls-eye from the planets pole of rotation, which, in this view, lies left of center. uranus lies almost on its side with respect to the other planets and is rotating in a counter clockwise direction, as seen here. Clouds in the Uranian atmosphere give rise to the pattern, the first clear evidence of banding similiar to that seen previosly on Saturn and Jupiter. The bandind on Uranus, however, shows much less contrast. At the distance at which the images were acquired, Voyager's camera could have detected individual features as small as 660 km. (410 miles) across, but no such cloud or markings were apparent. Scientists cannot yet say what properties, such as cloud height, composition, or particle size, are giving rise to the varying levels of brightness visible here. The images composing this picture were shot through a filter that transmits only violet light. in the original, unprocessed images, the contrast of features producing the banding is low, not more than 10 percent. In order to reduce 'noise' and enhance the visiblity of the features, processors combined five images and then compared the resulting composite to a hypothetical featureless planet illuminated by the Sun from the proper direction. Only the ratio between the original data and the hypothetical image is shown.