Winners - France
16 - 18 years old - Dione
We are students from France, entering the Cassini scientist for a day competition. We strongly believe that Cassini should image Dione, because it will yield the best science result. Dione, being one of Saturn's moon, is quite mysterious and it is our scientific duty to find out more about its structure, its matter and its past.
Firstly, since there might be a liquid layer underneath Dione's hard surface, it could be interesting to get more information by sending Cassini's spacecraft to get more images and try to solve this interesting mystery. What could this liquid be made off? Which properties could it have? How could it be possible? Like our moon's rocks, we could study it with more interest and discover new properties of moons' matter.
Secondly, this wonderful moon seems to have been turned around 180°, as shown by its crater patterns. It's the first time we see it in the Universe! It is thought that impacts of large objects from Saturn's rings might have caused this shift. The reasons for the shift is one of the mystery we have to try to solve. How can a celestial body shift on its axis? These craters are made by large objects from Saturn's rings and we could study the remains of these objects, which could tell us many things about Saturn's rings' rocks' properties.
Thirdly, the fact that we can see bright ice cliffs accross Dione's surface suggests that it may have had tectonic activity in the past. We could study this phenomenon and improve our capacity to prevent earthquakes and tsunamies on Earth. Since it has tectonic activity, it probably has radioactive metals in its core. Today it does not have tectonic activity anymore, which make us wonder : could this happen to the Earth?
Finally, as the next flyby will be in 2015, being the last time Cassini will get close to this fascinating moon, we should be prepared for this amazing opportunity. We should take many photos and discover more and more secrets about our Universe and maybe about Saturn. Dione, of all the targets, is the one we discovered at last, so the one we have to study because we know less about it.
To conclude, we urge you to select this incredible target, which is the most interesting target to study, because it's the one which leads us to think about incredible things, things that can only be studied on this moon!
16 - 18 years old - Iapetus
We are going to speak about the Cassini's project which is the project of spending a space probe on one of Saturn's moon and we are going to let you discover one of those most interesting one : Iapetus. You have to know that the Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
First we are going to tell a little more about this moon which is probably one of the most interesting moons in the solar system. It was discovered by Giovanni Cassini in 1671 and it is 1471 km in diameter. All around its equator, there is a ridge of very high mountains which some of them can even reach 10 kilometers (6 miles) in height. On this moon, there is almost no water because there is just 1,2 times the density of liquid water and, scientists think that the major part is made of ice and the rest is made of rock. Moreover, they have discovered that Iapetus rotation on Saturn's orbit is very slow with a period of about 79 days which is very small compared to our moon which completes its orbit around the Earth in approximately 27.32 days. But those two moons are not that different, they are both tidally locked to their respective planet which means that there is always the same side facing Saturn or the Earth. But the most interesting and mysterious part of Iapetus is the two different colors of its surface. Indeed, we can only see Iapetus on the west side of Saturn because Iapetus had one side much darker than the other side: one side is as dark as coal and the other one is covered with what looks like powered sugar.
So Cassini's project can teach us more about this intriguing moon like what is the exact height of the equator's mountains and what are their origin. Thanks to this project, scientists might be sure about Iapetus's composition. Moreover, the space probe could learn us more about where the slow rotation comes from. But the most important duty of this space probe would be to finally understand why there are two different surfaces on Iapetus. Scientists have already two hypothesis. The first one is that it might be due to the fact that the material have swept from a more distant, dark moon whose name is Phoebe. The second one is that the dark material may have been spread out by ice volcanism. Anyway, the only way to find the answer would be to send the Cassini's project on Iapetus.
So as you could see, Iapetus has still got a lot of mysteries which just ask to be solved and it just depends on us to finally find the answer of all these questions, so make the good choice and choose Target number one!
16 - 18 years old - Saturn
The reasons why we decided to choose Target 3
We have chosen Saturn because it is the symbol of all planets. Most astronomical books have Saturn as their cover. This planet is very imposing, with its rings, and is bigger than Jupiter! Saturn's rings have always awoken our curiosity : their formation, composition, reasons of existence. Tthey are also the most beautiful phenomenon out in space to us. We have always wondered why the rings' color wasn't homogenous. Moreover, infrared imagery has revealed that Saturn possesses a hot polar vortex which is unique in our solar system. Maybe we could learn more about this phenomenon quite unknown to us, it can only advance us in the scientific matter. We hope that our questions will be answered thanks to Cassini's expedition.
What may be discovered and useful/beautiful
As we already know, the rings of Saturn are made of frozen stones which can be as big as a pebble to the size of a house. The rings have a diameter of 280 000 kilometers but only a kilometer in thickness. The rings can be separated by “divisions”which are zones where Saturn's attractiveness and it's moons' make it impossible for these rocks to stay in those zones. The planet is made of a stone core which is covered with metallic hydrogen, then liquid hydrogen and finally, gaseous hydrogen. Saturn has an atmosphere and a very rare hot polar vortex.
What's more, Saturn has a lot of natural moons (up to 62). It is hard to say how many, because every heap is a satellite, technically speaking, and it is not possible to do the distinction between a big particle and a little moon. Many of them are unknown to us so we could learn many things about each moon (size, composition, atmospherical information…) and all we learn could lead to making some great posters on Saturn. Maybe shall we discover more things about the satellites of Saturn and it atmosphere using Cassini. By studying Saturn, we focus on the planet and all of its satellite.
Finally, the image, acquired by Cassini's visual and infrared mapping spectrometer, shows Saturn lit by its own internal, thermal glow. Clearly visible is a 60,000-kilometer-long (37,000 miles) string of bright "pearls," which are actually clearings in Saturn's deep cloud system. Scientists plan to continue observing this phenomenon over the next few years to try to learn more about Saturn's deep circulation systems and meteorology, that's why Saturn is a stupendous target.
As a conclusion, who wouldn't be intrigued by knowing more about the most breathtaking and splendid planet of our Solar system, to be able to navigate in a 3D map brought back by Cassini, and explore all of it's different moons and marvellous rings, and maybe be able to see and manipulate the different satellites that surround Saturn.