Titan: A New Astrobiological Vision From Cassini-huygens
- Paper number
IAC-07-A1.5.-A1.7.04
- Author
Prof. F. Raulin, Université de Paris XII et Paris VII, France
- Year
2007
- Abstract
After less than three years of close observation by remote sensing and in situ instrumentations from the Cassini-Huygens mission, Titan looks more and more as one of the key planetary bodies in the solar system for astrobiological studies. Titans does not look anymore like a frozen primitive Earth, but it looks now like an evolving planet, geologically active, with cryovolcanism, eolian erosion, clouds and precipitations, and a methane cycle very similar to the water cycle on Earth. But the new data also show that a very complex organic chemistry is taking place in the very high atmospheric zones of the satellite, with the formation in the ionosphere of high molecular weight (up to several 1000 Daltons) organics feeding the lower zones with these compounds, down to the surface. In spite of the low surface temperature, these organics are probably evolving once in contact with water ice and form organic molecules of biological interest. This evolution may explain the reflectance spectrum of Titan’ surface observed by the DIRS instrument on Huygens, although, the lack of spectroscopic data in the near IR makes difficult the retrieving of these data. Thus, contrary to what was expected, the organic chemistry on Titan seems mainly concentrated in the ionosphere, on the surface and in the aerosols. These aspects will be examined, some of the associated questions will be answered on the basis of the already available Cassini-Huygens data. The needed post Cassini exploration and the associated future instrumentation will be also discussed.
- Abstract document