Solving the mysteries of Saturn’s enigmatic moon

Just a few months after the Huygens probe – the farthest-reaching, man-made object to ever land on a solar system body – touched down on the surface of Titan, the world has been receiving singular images from the surface of Saturn’s giant, enigmatic moon. The new data is being processed by Greek astrophysicist Athena Kousteni, a staff member of the French National Center for Scientific Research, who explains that the Cassini mission (launched from Cape Canaveral, Florida on October 15, 1997) is «the most far-reaching and ambitious mission of the European Space Agency.» [The mission is run jointly by the ESA, NASA and the Agenzia Speziale Italiana.] Sister planet The scientist notes that the earliest images received from Titan’s surface showed volcanoes spewing ice and channels of liquid methane that flow into lakes. Early data also estimates that Titan’s atmosphere is made up mostly of nitrogen but that there is also methane and many other organic compounds, similar to Earth. Scientists estimate that the conditions on Titan are very near those that prevailed on Earth millions of years ago. «Titan resembles our planet more than other heavenly body,» explains Kousteni. «It is very much an ideal laboratory to study the conditions that used to prevail on our planet. The methane and the various chemical reactions in the atmosphere create organic compounds that compose the basis for the evolution of life forms.» The Cassini-Huygens mission is a unique technological achievement. It has penetrated the solar system farther than any other to a distance nine times that between the Earth and the sun, or 4.5 billion kilometers. «This is the first time we have succeeded in landing a machine on the surface of such a distant heavenly body. It was something of a wager for the ESA, which wanted to prove that it has the technology and know-how to achieve such a feat,» says Kousteni. In order to reach its final destination, instead of using rocket fuel, the Cassini spacecraft (which was carrying the Huygens probe) used the gravity fields of the planets it passed as a propeller to move it forward, reaching Titan eight years after its launch. Astrophysics doctoral candidate Panayiotis Lavas explains that before launching the Huygens probe, the Cassini orbited Titan three times, taking measurements of the moon’s atmosphere so that the evaluations scientists had made before its launch could be confirmed. First images Images from Titan so far show that the moon canals lead to large black spots, which some scientists say may be lakes that are or once were filled by liquid methane. Images also show volcanic formations which, however, spew ice rather than lava. «Titan is geologically active,» says Lavas. «The surface and sub-surface are inactive but are constantly changing.» As far as the moon’s atmosphere is concerned, the scientists says that it experiences extreme phenomena, such as winds reaching speeds of 160 meters per second. The data received by the Huygens probe so far covers just 1 percent of Titan’s surface. Over the next four years (which is how long the probe’s fuel supplies will last), this amazing piece of technology is expected to solve many mysteries and answer many questions about Earth’s «sister.»