The lakes and seas of Titan



The study of Titan, Saturn's largest satellite, is a major goal of the Cassini-Huygens mission. This joint project between NASA, the European Space Agency, and the Italian Space Agency consists of a Saturn orbiter (Cassini) and a Titan probe (Huygens). Since the mission's arrival at Saturn in July 2004, one of its most spectacular discoveries has been the finding of the first extraterrestrial nonmagmatic standing bodies of liquid: Titan's hydrocarbon lakes and seas. In July 2006, the first synthetic aperture radar (SAR) images of Titan's north polar region obtained by the Cassini spacecraft showed dozens of lakes above latitudes of 70° [Stofan et al., 2007]. Subsequent SAR images obtained by Cassini have covered approximately 68% of Titan's north polar region at latitudes above 60 degrees. These images show more than 400 radar-dark areas that we interpret as being liquid lakes (shown in dark blue in Figure 1), including a few that are so large that they rightfully may be called seas. We discuss here the evidence for liquids on Titan, the distribution and morphology of lakes, and recent data that indicate the presence of lakes in the south polar regions.