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International Edition Winners - 2013: Romania, Target 2, Grade 9-12

International Edition Winners - 2013: Romania, Target 2, Grade 9-12

Target 2, Dione
Buţiu Ioan Ştefan, Chiţoiu Andreea-Leona, Cîrjan Ana-Maria

Grade: 9-12

Teacher: Carmen Tânâsescu

School: "Andrei Şaguna” National High School

City: Braşov

"Observations made by the Cassini orbiter on three separate flybys of Dione, Saturn’s fourth largest moon, might make this icy satellite a new point of interest in our Solar System. The questions raised by the probe’s data merit further investigation and make Dione a prime candidate for more detailed exploration.

One intriguing aspect of Dione is its geology. We know that about a third of it is comprised of a rocky core and that it has an icy crust, but what about the rest? The Cassini’s observations offer evidence of a subsurface ocean. For example, the probe detected a faint stream of particles emanating from Dione, similar to those spewing from Enceladus. This, along with the network of icy cliffs located on Dione’s trailing hemisphere, which are akin to the “tiger stripes” of Enceladus, indicates tectonic activity which would have necessitated a liquid interior. Furthermore, the peculiar topography of Janiculum Dorsa, an 800-kilometer-long mountain apparently formed in a crease in Dione’s surface suggests that the crust was once warm. The most likely way this was achieved was through the presence of a subsurface ocean which would magnify the effect of tidal heating caused by Saturn’s gravitational pull by as much as ten times. These clues support the enticing possibility of liquid water under Dione’s surface, which would increase its astrobiological potential, and definitely warrants further observation.

A second argument for selecting Dione is to determine the geological processes that created its distinctive surface. Dione differs from other moons through the fact that its trailing hemisphere is more heavily cratered than its leading one, whereas the inverse is true for most satellites. Due to its relatively small size, an impact causing a 35 kilometer crater would have been sufficient to spin the moon. Since we can observe many craters larger than that, it’s probable that it was spun repeatedly. Could this have anything to do with the decline in geological activity that we can deduce happened at some point in Dione’s history? Perhaps these impacts affected Dione’s orbit and determined a reduction in tidal heating. And how come the moon seems to have spun exactly 180 degrees? In addition, Dione’s trailing hemisphere also displays a remarkable network of ice cliffs, some of them hundreds of meters high, formed by enormous tectonic fractures. Are they remnants of a bygone era of geological exertion, or do they continue to evolve at a slower pace? Answers to questions such as these may provide valuable insights into the inner workings of icy moons similar to Dione, the places most likely to support life in our Solar System.

To conclude, the details unearthed by the Cassini probe regarding Dione have raised questions about this once boring moon whose answers may prove invaluable. Through careful examination of Dione, we stand to gain much in the way of understanding the history of our Solar System, the intricate interactions of celestial bodies, and the the possibilities of life on the icy moons of our Solar System."

  • Blend space exploration with reading and writing -- Reading, Writing & Rings!
  • Cassini Scientist for a Day -- Students get involved
  • Cassini Raw Images