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2013 Edition -- Target 1: Iapetus, Grade 7 and 8 Winner

2013 Edition -- Target 1, Grade 7 and 8 Winner


Gracie Stewart
Iapetus
Target 1, Iapetus
Gracie Stewart

Bull Run Middle School
7th Grade
Gainesville, Virginia

Teacher: Courtney McDonald




"Ever since NASA sent the Cassini Spacecraft into outer space, it has been gathering not only amazing photographs, but also vital and interesting knowledge about Saturn and its moons. Although photos from all targets will help improve our knowledge of our solar system, I believe that a photograph of Iapetus will prove to be the most rewarding for many reasons.

My first reason for this belief is that there is a great dichotomy on its surface. The side of Iapetus leading its orbit is dark, coal black, while the other side is a bright white. Many theories for this odd color contrast have been formed, but no real cause has been proven. It could be anything from ice volcanism, to dark particles from the moon Phoebe, to the more likely theory of thermal segregation. I believe that photographing this moon could assist in solving this mystery.

My second reason is that it would be fascinating to learn the cause of Iapetus's peculiar shape. It is thought that walnut-like shaped was caused millions of years ago by a much faster rotation, but others believe that the cause is bulging from water or a liquid of sorts underneath the surface. If a stream, river, or even erosion caused by a liquid is found in a photograph, it would prove that the second theory is correct. Also, finding proof of liquid could lead to further investigation about the composition of that certain liquid.

Lastly, Iapetus's surface contains many craters and a long equilateral mountain chain. Cassini has shown photographs of hexagonal or pentagonal craters, so it is to my curiosity if those craters were just an odd occurrence, or are there a substantial number of them? As for the mountains, there are currently two logical reasons for them. One being that Iapetus once had its own satellite which burned and the debris fell into a mountain range, or that Iapetus once had a rotation so fast that gradually mountains rose. I believe that if a photograph of the mountains reveals that they are primarily rough and ragged, it would provide more reason that it was a small satellite that burned, but if the mountains are depicted as being fairly smooth, it would lead me to believe that it was caused by a fast rotation.

Overall, I believe that a photograph of any of the three targets would greatly enhance our knowledge of the universe and create a magnificent photo, but capturing a photograph of Iapetus would surly prove itself more valuable to science."