Astr110 Photography Projects, Fall 2004

Saturn - Cat Rau, Stacy DeVries, Ratko Bojanovic

Saturn, the second largest planet, separated from the sun by five other planets, is the least dense of the planets. This planet located 9.54 AU from the sun is composed of mostly hydrogen (75%) and helium (25%). Saturn's most distinctive feature is its rings. Galileo first observed it with the telescope in 1610, and the geometry of the rings were not completely understood until 1659 by Christiaan Huygens. Saturn was the only known planet with rings for the next 300 years.

The rings, evident in this picture, are actually made of countless individual particles, in size varying from small dust particles too small to be photographed up to large boulders, which all orbit together making it look like a solid disk. Through spectroscopy, scientists are able to tell the make up of these particles which is a water ice with a high-albedo. The rings alternate bright and dark in different areas, creating a look of various rings placed next to each other. This ring effect is caused by the amount of particles in an area, where there is few particles it appears transparent and where there are a lot of particles the Sun's light reflects more and they appear brighter.

References:
Jeffrey Bennet, "The Cosmic Perspective", San Francisco, CA 2002 A.D. http://www.nineplanets.org/saturn.html