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Ad Astra! News and Discoveries from the the Cassini-Huygens Mission to Saturn
29 Oct, 2007 01:01 pm
The Cassini-Huygens mission was launched on 15 October 1997; 10 years later, we speak to Professor Andrew Coates, head of Planetary Science Group in the Department of Space and Climate Physics at University College London. In this interview, Professor Coates discusses the purpose and certain exciting discoveries of the mission, especially pertaining to the atmosphere of Titan, one of Saturn's moons, and the icy water jets recently observed on Encelades, another satellite of Saturn.
What it is for is to go to different planets and trying to understand its system. We had a tantalizing look with the Pioneer and Voyager spacecrafts, and it was so interesting that we had to go back. The previous spacecraft [that] went to Saturn did not have the imaging equipment to peer through Titan's [a moon of Saturn] haze, and Cassini is equipped to not only look underneath the clouds of that fascinating moon but also had the Huygens probe, which could land on the surface of Titan.
What has happened in these 10 years since the launch?
Once of the recent discoveries was the 60th moon of Saturn; only 30 or so moons were known at [the time of Cassini's launch]. [It has also allowed us] to look at the dynamics of the ring system, how the ring systems interact with the plasma environment, how spokes form in the rings, how the rings have their own atmosphere...
Can you tell us about the icy water jets recently observed on Encelades, a satellite of Saturn?
We did not expect to see these [so-called "tiger stripes"] coming out of the south pole of Encelades, [discovered] by the magnetic field instrument on Cassini. This seems to be the source of jets, or geysers, of material, mixtures of ice and dust, coming out of the Southern hemisphere. This is a bit strange because Encelades itself is not that large of a moon, so there should not be sources to heat this icy body up to produce all this activity. It is an exciting discovery because this is watery stuff, which perhaps points to the fact that there might be liquid water under the surface of Encelades...Water, anywhere in the solar system, is interesting.
Interview by Audrey Wang
Saturne, la sonde Cassini-Huygens par Winstars 2 - Juin 2005