13-15 years old: The lakes of Titan
Author: Lilly Friedmann
The reasons why I have chosen Titan’s lakes are that I am fascinated not only by the giant lakes but also by the fact that this moon of Saturn has many similarities with our Earth and its moon, more than with anything else in the whole solar system. One example is that the chemical elements in the moon’s atmosphere are similar to the elements that existed on Earth before life started to develop on it. What fascinates me about Titan’s lakes is that they are made of liquid methane, that they evaporate after a certain time and rebuild themselves to new clouds, just like the water cycle on earth.
Titan is the biggest moon of Saturn (and the second biggest in the solar system). It is an exciting moon as it is in some aspects an earth-like planet. Titan is rich in nitrogen and is many kilometres thick. The Titan lakes and rivers consist of liquid methane and other hydrocarbons. Very close to the Titan surface, there are methane clouds from where it rains methane. In this way, the lakes and rivers have developed over a long time. After a while, the methane from the lakes evaporates and builds again new clouds in the atmosphere. This cycle is very similar to the water cycle on earth. The liquid methane has not only built the lakes but has also created erosions on the moon’s surface. These lakes of liquid methane are located at Titan’s North Pole. From space, the lakes look like blue spots. The biggest Titan lakes are much bigger than the lakes e.g. in North America.
In my opinion, the Titan lakes should be explored much more as a lot of things are still unclear. For example, why cannot we see any waves on the flat surface of the lakes although it is confirmed that there is wind on that moon? Another question is why so many lakes are located so close together in one spot, namely at the North Pole? As the methane from the lakes evaporate into the atmosphere, they could build new clouds anywhere, not only at the North Pole. But the big majority of them are found there.
I also ask myself how the methane gas has managed to get through the ice surface of Titan and then build a valley where the gas is staying. Moreover, it would be interesting to know if Saturn and Titan have a relation just like the earth and our moon. With the magnetism between earth and moon, we have e.g. the tides in our seas, maybe something similar exists between Saturn and Titan. Also, the valleys and curves on the surface of Titan look similar to those on earth, how exactly have they been shaped in the long past?
What could we do with so much methane gas? In the future, maybe we could use it to produce some kind of energy? There is also too much methane gas on earth - maybe we could find ways to reduce methane gas by experimenting with the methane gas on Titan?
All in all, I think there are so many interesting questions about Titan and its lakes, how all this has developed and why. There is so much more to explore about the circumstances on Titan that I think it is the most valuable target to follow.
16-18 years old: Ice plumes at the south pole of Enceladus
Author: Jan Fischer
The Cassini spacecraft has been orbiting Saturn since 2004 and successfully landed the Huygens probe on the moon ‘Titan’ in January 2005. Before it will drop onto Saturn in September 2017 it could travel to one of the following possible destinations: the ‘great lakes’ of Titan, the north of the planet itself with a hexagonal shaped cloud pattern, or ice plumes at the south pole of Enceladus - one of Saturn’s moons.
The mystery of Saturn’s hexagonal cloud pattern has been solved: Physicists at Oxford University have been able to recreate this cloud pattern in an experiment. Therefore, further images of this phenomenon would be, although pretty, of little scientific relevance.
Titan’s oceans: Kraken-, Ligeia-, and Punga Mare are fascinating. Giant pools of ethane and methane that in theory might even support life should be explored and studied further, no doubt about that. But with the few possibilities we have for those explorations, at least for now, we must prioritize. And the south pole of Enceladus will lead to more scientifically relevant revelations.
Enceladus is Saturn’s sixth largest moon. It is about 500 km in diameter, has a great ice shell at its surface with liquid water underneath it, and is believed to be the most likely candidate to support some form of life in our solar system, apart from Earth. Finding life on an alien rock would be another ‘giant leap for mankind’!
Now, our Cassini ship was not designed to analyze an environment with focus on whether it can support life. Cassini takes pictures with wide- and narrow angle cameras and it can create images with an ultraviolet spectrograph enabling it to ‘see’ beyond the visible spectrum of light. But it also has a cosmic dust analyzer which detects the composition of particles that hit the spacecraft. With that, Cassini can analyze particles that have been blast out of the moon by the ice plumes at the south, and so it might find microorganisms that have lived in the ocean under the ice. In 2015, a similar project was already conducted with promising results for possible life forms, it would be helpful to see if in two years there have been changes in the composition of the dust and to gain more samples that lead us to a definite answer: ‘Yes, there is life on Enceladus’ or ‘no, there is not’.
Further images from a close distance will also reveal more about the development of the ice geysers whose emission dropped from 2005 to 2015 by maybe 40 percent. Old geysers shut down and some new ones erupt – this progress could be observed in detail if we get new data in the following year.
'Enceladus’ spectacular cryovolcanic activity, tectonic resurfacing, and the presence of a plume of water and other materials erupting from its south pole make it a compelling target for astrobiological exploration.” - Physicist and Astronomist Christopher D. Parkinson from his paper: ‘Habitability of Enceladus: Planetary Conditions for Life’