Winner - Germany
Author: Hye Young Lee
Cassini- Huygens mission is an international project planned by NASA, ESA and ASI. A spacecraft, composed of NASA's Cassini orbiter and ESA's Huygens probe, has entered orbit around Saturn in 2004. When the Huygens probe passed through ‘Titan', a moon of Saturn, it could measure the atmosphere and surface, supplying sufficient data for the scientists. I think ‘Dione' would also be an efficient and interesting target to investigate, because the instruments within the spacecraft might be able to support new discoveries about this mysterious moon.
Dione, a small moon of Saturn with a diameter of 1123 km, has several unusual characteristics.
First, there are bright thin lines that seem to be fractures across the surface, and a liquid layer is estimated to be underneath the hard, rough surface. Using ACP, aerosol collector and pryolyser, the scientists can get data for chemical-composition analysis. The DISR, descent imager/Spectral Radiometer, can take images so that the scientists can have a closer look to the bright thins lines. SSP, surface science package will be useful to investigate the under layer of Dione.
The bright ice cliffs on Dione suggest the occurrence of tectonic activity in the past. If there was a tectonic activity, the surface would've cracked, and some internal gas would've been exposed. Then, the instruments within the spacecraft could deduce atmospheric properties using radio signals. Moreover, HASI, Huygens atmosphere structure instrument could be used to measure the physical and electrical properties of the atmosphere, and GCMS, Gas Chromatograph could be used to get chemical data about the gas.
The deeply crated surface of Dione is estimated to be the damages of big objects from Saturn's rings. The DISR can take a picture of it for a more detailed investigation. It can also take some pictures of the objects around Dione, to predict what kind of objects hit the Dione. SPP can find out the physical properties of the surface. Some fractures of the object that hit the Dione could be found on the surface and the size of the crater could determine how great the collision was, and how big the object would be.
Several properties of Dione can be discovered using the instruments. These properties can be compared with other moons such as titan to discover the similarities between general moons around Saturn. The thickness of the atmosphere could be predicted by knowing how quickly sound and light waves travelled on the moon. Chemicals in the atmosphere, occurrence of clouds and lightings, physical and electrical properties of the atmosphere could be compared.
In conclusion, the Cassini spacecraft should image the Dione, because the investigation will offer great quantity of information. Scientists will be able to get more precise data and images of Dione, and the datas will enable some predictions of other moons around Saturn to take place as well. 2015 is the last chance for the Cassini spacecraft to get close to Dione. Therefore, the Cassini spacecraft should definitely target Dione.