Planetary rings - nebular material from which Saturn...

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Planetary rings The rings of Saturn (imaged here by Cassini in 2007) are the most massive and conspicuous in the Solar System. [31] False-color UV image of Saturn's outer B and A rings; dirtier ringlets in the Cassini Division and Enke Gap show up red. Saturn is probably best known for its system of planetary rings , which makes it the most visually remarkable object in the solar system. [31] The rings extend from 6,630 km to 120,700 km above Saturn's equator, average approximately 20 meters in thickness and are composed of 93% water ice with traces of tholin impurities and 7% amorphous carbon . [69] The particles that make up the rings range in size from specks of dust up to 10 m. [70] There are two main theories regarding the origin of the rings. One theory is that the rings are remnants of a destroyed moon of Saturn. The second theory is that the rings are left over from the original
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Unformatted text preview: nebular material from which Saturn formed. Some ice in the central rings comes from the moon Enceladus' ice volcanoes. [71] Beyond the main rings at a distance of 12 million km from the planet is the sparse Phoebe ring, which is tilted at an angle of 27 to the other rings and, like Phoebe , orbits in retrograde fashion. [72] Some of the moons of Saturn, including Pan and Prometheus , act as shepherd moons to confine the rings and prevent them from spreading out. [73] Pan and Atlas cause weak, linear density waves in Saturn's rings that have yielded more reliable calculations of their masses. [74] In the past, astronomers believed the rings formed alongside the planet when it formed billions of years ago. [75] Instead, the age of these planetary rings is probably some hundreds of millions of years....
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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