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Cassini Scientist for a Day -- 2010 Edition Winners Target 1: Rhea, Grade 9 to 12

Cassini Scientist for a Day -- 2010 Edition Winners Target 1: Rhea, Grade 9 to 12


Hillary Fischer
Rhea
Rhea
Hillary Fischer

12th Grade
Beatrice High School
Teacher: Joan Christen
Beatrice, Neb.


"Rhea, Saturn's second largest moon, is the best choice for observation when the next flyby occurs. It is a peculiar planet that needs to be studied more. There are three main reasons to study Saturn's second largest moon, to try and find what caused the "wispy" formations on its surface, how being made of mostly water affects Rhea's rotation and what is the gravitational pull of Rhea.
The surface of Rhea is covered in wispy formations. These formations bring about the question "what caused strange fixtures?" Rhea is thought to have been tectonically active at one point. But why would Rhea still be moving? Was the temperature not always so cold as to allow water to turn into a liquid and move under the surface or on the surface? Possibly studying the formation of the wispy formations on the dark side of Rhea could offer some answers by finding the direction of the formations and using the laws of physics to calculate the initial starting distance of the fissures. Were these fissures cause from meteor showers striking the surface on the light side of Rhea or are they the result of years of tectonic movement? By acquiring pictures, perhaps answers to these questions could be found.

Another reason why Rhea is such an interesting target to choose is that Rhea is unusually light for its size. Its density is 1.233 times that of liquid which leads scientists to believe that it is three-fourths water. Where did the water come from? How did it turn into a spherical figure that orbits Saturn? No one knows what the core of Rhea is made up of. When the inertia of Rhea's axis was measured, it was found that it had a higher value than that for a solid core. Rhea has two sides, a dark side and a light side. On the light side there are craters and on the dark side there the previously mentioned "wispy" fissures. The light side is constantly facing the surface of Saturn like Earth's moon. It would be interesting to find out if the reason Rhea has fissures is because of the constant pull from Saturn. ?

The final reason why Rhea should be picked as the target to study is because no one knows if Rhea has rings. Does Rhea has a high enough gravitational pull to hold in orbit any rock material? Does the core of Rhea, which some believe to be a homogenous mixture of water and rock, have the power to attract and hold anything? If Rhea does have rings, are these the same rings made up of the same material that cause the craters on the lighter side of Rhea? ?
All of these questions are wonderful reasons why Rhea should be chosen as the Cassini Titan Flyby target. Perhaps pictures can help us solve these questions. Rhea is a very interesting moon although it is only the second largest moon to orbit Saturn."