2013 Edition -- Target 2: Dione, Grade 9 to 12 Winner
2013 Edition -- Target 2, Grade 9 to 12 Winner
|12th Grade |
Queensbury, New York
Teacher: Nancy Palmer
"Titanic among moons, it dwarfs all known smaller satellites combined. With a frigid shell, battered landscape, and unique scientific signature, this fascinating and foreboding world is a land of living mystery. The object? Dione, an elegant sphere of cosmological insight.
Exhibiting 3,964,776.51 km2 of surface area with a 1123.3km diameter, Dione is a sizable satellite. That hefty real estate provides a striking backdrop for Dione’s intricate topography, littered with scores of geologic and impact demarcations.
With almost every Dione riddle emanating from the icy crust, a plethora of perplexities remains unresolved. Perhaps the most intriguing is Dione’s greatest oddity, the moon’s apparent flip. Akin to Earth’s satellite, Dione shares a tidal lock with its parent planet. This seemingly unremarkable behavior is betrayed by a gargantuan surface quirk: an unusual crater disparity between Dione’s leading and trailing hemispheres. On the leading half, light impact fields, with miniscule crater sites less than 30km in diameter. In contrast, the trailing edge manifests heavy scarring, with voluminous craters reaching 100km in stature. The polar opposite of astrophysical projections, Dione’s bizarre layout is best explained by a 180 degree pivot.
What initiated such a chaotic shift? Numerous craters substantiate violent collisions in Dione’s past, many from sources large enough to spin the moon. Is this the underlying cause of Dione’s planetary pirouette? Could an unforeseen force be the catalyst? The definitive imagery lies within Cassini’s research bailiwick.
Analogous to many Saturnian satellites, Dione maintains a mean motion orbital resonance with a neighboring object. Enceladus forms Dione’s principal dance partner, the two bodies bound by a 1:2 ratio. This relationship has profound effects on Enceladus, driving the cryovolcanic geysers that make this moon a scientific standout. Despite such dramatic external influence, a limited level of dynamism has been observed on Dione. Why does this interaction appear so one-sided? Cassini’s cameras might unveil the true nature of this bond.
In 2010, Cassini unlocked a provocative variable in Dione’s narrative: a gossamer exosphere, so delicate that a singular oxygen ion accounts for 0.67 cubic inches. At the time of observation, high background radiation levels precluded Cassini from unveiling exospheric water, inhibiting a definitive understanding of the exosphere’s existence. Yet the riveting factions of this structure merit follow-up investigations. Conceivably, enhanced sublimation components via Saturn’s robust radiation belts could be fueling the process.
Recently, Dione has played host to an exciting new possibility: a justifiable locale for a subsurface ocean. Studies into Dione’s impressive mountain, Janiculum Dorsa, revealed topical bending, synonymous with support of warm, subsurface water layers. By expanding this hypothesis, Dione could serve as an evolutionary roadmap for icy moons like Europa. Such research would allow Dione to be viewed through an astrobiological lens, probing potential new formats for sustainable life.Though numerous enigmas surround Saturn, Dione stands unique. A research model for the future and geophysical bridge to the past, few satellites spark such mystique, curiosity, and scientific opportunity. In cosmic poker, Dione holds the stakes---and Cassini can force the defining hand."