Saturn’s rings

Water can be found, in all three aggregate states, almost everywhere in the universe as ice in the liquid phase on the satellites of the outer solar system, including Saturn s rings and in the gaseous state in the atmospheres of Venus, Mars and Jupiter and in comets (as can be shown, for example, from the IR spectra of Halley s comet). The OH radical has been known for many years as the photodissociation product of water. 

The moons of Saturn have a direct influence on Saturn s rings. A natural tendency of ring materials is to spread both toward and away from the planet, but the moons and a complex interplay of gravitational forces shape the rings and define their structure. Mimas. . . Tethys. . . Dione. . . Rhea. . . Enceladus. . . Iapetus. . . And Hyperion. . . ... 

The moons of Saturn have a direct influence on Saturn s rings. A natural tendency of ring materials is to spread both toward and away from the planet, but the moons and a complex tnterplay of gravitational forces shape the rings and define their structure. 

Hagaoka used the mechanical description of Saturn s rings as a model for orbital electrons to explain the radiation formulae for line and band spectra and to propose a speculative mechanism for radioactive decay. 

Like the periodic table of the elements (Chapter 4) and gaps in the asteroid belt, the spacing of Saturn s rings fits a numerical pattern based on the golden ratio [72]. 

The Cassini spacecraft took this image of Saturn s rings using the Ultraviolet Imaging Spectrograph. It shows there is more ice (turquoise) than rocks and dust (orange) in the outer parts of the rings. 

The strong spectral absorptions due to water ice and frost dominate the spectra of most outer planet satellites. Water ice was first firmly identified in infrared spectra of Saturn s rings (Pilcher et al., 1970) and then Europa and Ganymede in 1972 (Pilcher et al., 1972). Since then water ice/frost... 

Hobson (1993) has recently developed a method for computing this unstable manifold to very high accuracy. As expected, it is indistinguishable from the strange attractor. Hobson also presents some enlargements of less familiar parts of the Henon attractor, one of which looks like Saturn s rings (Figure 12.2.4). 

M.I. Mishchenko, On the nature of the polarization opposition effect exhibited by Saturn s rings, Astrophys. 3.411,351-361 (1993). 

Cassini, Giovanni Domenico (1625-1712) Italian-bom French astronomer, who was professor of astronomy at Bologna. In 1669 he moved to Paris to run the new observatory there, becoming a French citizen inl673. He is best known tor his discovery (1675) of the gap that divides Saturn s ring system into two parts, now called the Cassini division. He also discovered four new satellites of Saturn. 

Awarded a prize in 1859 for his essay On the Stability of Saturn s Rings , which described the nature of Saturn s rings as numerous small particles rather than a solid or fluid ring. 

The study of Saturn s rings led Maxwell to the problem of the motions of large numbers of colliding bodies, such as would be found in the rings. This in turn led him to the study of gas kinetics. Here he introduced the use of statistical methods, not for data analysis but for a description of the physical process. He recognized that there must be a distribution of velocities of gas particles, and by 1860 he had developed a statistical formula for that... 

The first detailed examination of ring dynamics was accomplished by James Clerk Maxwell in his 1857 Smith Prize essay, a study that still repays reading. He dealt with the question of the composition and stability of Saturn s rings, demonstrating that they must consist of a swarm of small particles trapped in planar orbits. The demonstration of differential rotation in the Saturn rings by the observation of Doppler shifts in a reflected solar spectrum was first performed by Keeler about 30 years later. 

This spacecraft is a scientific probe that was sent to study Saturn, Saturn s rings, and its moons. To withstand the transit through the asteroid belt and the Saturn micrometeoroid environment, Mylar was used in a Whipple shield arrangement (Section 10.4.2.4.2). It served the dual purpose of micrometeoroici protection and multi-layer insulation (MU). The standoff distance from the secondary shield varied from 2.5 inches to 18 inches. In some critical locations on the spacecraft, fuel tanks for example, two layers of beta cloth were added behind the Mylar. 

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