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International Edition Winners 2011: Pakistan, Target 2, 11-12

International Edition Winners 2011: Pakistan, Target 2, 11-12


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Photo not available
Rhea and Titan
Rhea and Titan
Sidra Fatima Naqvi

12th Grade
Westminster School & College
Islamabad, Pakistan




"The two largest moons of Saturn, separated by over millions of kilometers appear in a striking proximity in this photo. Rhea and Titan - one is a frozen ball of ice, the latter mainly rock in its mysterious hazel halo. Such a beautiful contrast intrigues one to learn more about the geological makeup of the moons, and compare it to that of planet earth's. Therefore, Target 2 gives the best choice of imaging.

Titan is the only known moon to have its own atmosphere rich with nitrogen, just like earth. However, it lacks oxygen and has an extremely low temperature unfitted for life as we know it. Although, it has a weather system much similar to that of earth's, it is the hydrocarbons mainly methane vapours, which rain down from clouds and flow in streams and channels into basins and lakes across the eroded land, in contrast to earth's water cycle. Recently, it has been proposed that Titan has oceans too, but the true chemical nature of their composition has not yet proved. And whether there can be deeply buried frozen reserves of water or not, Saturn-Titan system mission - a floating probe to be detached by Cassini on the surface of Titan's oceans - can capture more information. Astrobiologists thus justifiably claim that Titan represents young earth in its prebiotic state billions of years ago.

Establishing that, Target 2 can help us answer many questions about the origins of life on earth. Here we can bring Rhea into light. This moon of Saturn is airless except for the occasional wisps of oxygen and carbon dioxide when the frozen water decomposes as struck by high energy particles in the Saturn's rings (or does it have its own ring system creating magnetic radiations?). This shows that there can be reserves of water and oxygen found throughout the solar system - a promise of life of some form. Scientists suggest that the cause of carbon dioxide and carbon rich material in creviced surface of Rhea may be micro meteors bombarding it. In similitude, can asteroids and comets be what brought water and organics to earth and raised its temperature gradually to a degree which could support life? Cassini can find it out for us.

Although Rhea and Titan differ a lot in size and mass, both have enough gravity to hold atmosphere. Titan has a very dense one with basic elements just that needed for the building blocks of life - the nitrogenous bases of the DNA. If Cassini explores in depth, we can learn more about evolution theory and whether it were some metallic catalysts found in atmosphere which brought about biochemical reactions leading to life on earth? And what is the prospect of life on Titan or Rhea, or even more far-fetched, can Rhea in some way serve as a supply of oxygen and water to Titan? In later years, Titan with its reserves of nitrogen and methane can initiate space engineering and help obtain fuel which is so scarce on Earth."