On the occasion of the fifth anniversary of the European Space Agency's Huygens probe landing on Saturn's moon Titan (14 January 2005), approximately a hundred international scientists and engineers met at the CosmoCaixa Science Museum, in Spain, to assess what was discovered and what remains to be done by future spacecraft missions to Titan and the Saturnian system. The Huygens probe was deployed from NASA's Cassini spacecraft.
Speakers at the meeting pointed out that discoveries from the Cassini-Huygens mission have shown that Titan is much more interesting than even their wildest expectations more than 20 years ago when the mission was conceived, in the 1980s, several years after the Voyager flybys. Perhaps most stunning are the many similarities between Titan and the Earth. Though there are important differences, when one views the lakes and seas, the fluvial terrain, the sand dunes, and other features through the hazy, nitrogen atmosphere, it calls to mind the geological processes that created analogous features on the Earth. On Titan it has been discovered that frozen water plays the geological role of rock, and liquid methane takes the role of terrestrial water. As Saturn proceeds along its orbit about the Sun, the seasons change on Titan. The seasonal effects on the transport of methane are starting to be seen. A large lake in the south polar region seems to be getting smaller as winter sets in.