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2001 Edition -- Target 1: Hyperion, Grade 9 - 12 Winner

2001 Edition -- Target 1: Hyperion, Grade 9 - 12 Winner


Meera Ramakrishnan
Hyperion
Hyperion
Meera Ramakrishnan

10th Grade
The Winsor School
Boston, Mass.

Teacher: Mary Espanol


"Target one -- Hyperion -- presents the best opportunity for scientific investigation from the Cassini Space Mission. Hyperion is a small moon of Saturn, distinguished by its potato-like shape, its chaotic orbit, and its unexplained sponge-like structure. With an average diameter of 270 kilometers, it is the largest known non-spherical body and one of the strangest moons in the Solar System. It is an outlier in many respects, but by studying outliers we can learn a lot more about the nature of our universe, our solar system, and even the origins of life.

After being a mystery since its discovery in 1848, Hyperion yielded some of its secrets to Cassini as the spacecraft flew close by on September 26, 2005. New images taken by Cassini at a distance of 500 kilometers from Hyperion changed our understanding of this world forever. These pictures show a surface dotted with dark-floored craters and modified by some process, not yet understood, to create a strange, "spongy" appearance, unlike the surface of any other moon. Hyperions density is about half of that of water, possibly due to its high porosity of around 40%. Hyperion shows a dull reddish color with a low reflectivity (or albedo), averaging 0.3, which is much lower than the inner moons such as Rhea (0.7), Dione (1.0), and Enceladus (1.4). Further investigation will help define the different physical mechanisms that created the surface of Hyperion and will illuminate various planetary processes that shape the bodies in our solar system.

Secondly, investigation of Hyperion will help us advance celestial mechanics. Hyperion orbits at a mean distance of 1,481,100 kilometers from Saturn in an eccentric path. Its rotation is strongly influenced by its resonance with Saturns largest moon, Titan, which orbits at 1,221,850 kilometers. Titan apparently keeps Hyperion's orbit eccentric rather than growing more circular over time. Hyperion rotates roughly every 13 days during its 21-day orbit, but its trajectory is chaotic, with its axis of rotation wobbling so much that its orientation in space is unpredictable. Key questions that this raises are: Will Hyperion's rotations remain chaotic forever? Under what circumstances could it become stable? Do any of the small, irregular moons with unusual orbits also rotate chaotically?

Finally, NASAs Cassini spacecraft has revealed cup-like craters filled with dark substances. Water and carbon dioxide ices were found, as well as dark material that fits the spectral profile of hydrocarbons, like methane. Such molecules, when embedded in ice and exposed to ultraviolet light, form new compounds of biological significance. This is further indication that the basic chemistry needed for life is widespread in the universe. The unique conditions on Hyperion present a compelling opportunity to investigate the possible origins of life in our universe.

On its most recent flyby in September 2011, Cassini collected vast amounts of information. By investigating further, we can address some of the fundamental questions about universe and life. How exciting will that be?"