http://bactra.org/notebooks Cosma's Notebooks en http://bactra.org/notebooks/2009/04/10#titan <P>The largest moon of Saturn. It's large enough to have its own, fairly dense, atmosphere, and really the only reason it's a moon and not a planet is that it orbits Saturn, rather than directly orbiting the sun. That atmosphere is why I'm interested in it: it is (or at least this was the theory about ten years ago) a very weird mix of nitrogen and hydrocarbons, with some evidence of a sea of liquid methane underneath. This is not just very bizarre, in its own right --- a sort of freezing smog --- but also very promising for the formation of complicated organic polymers. Of course, it's been ten years since I did any serious reading about this, in which time a lot, no doubt, has been learned... <P><strong>Update, 21 January 2005</strong>: Huygens has landed. There are <a href="http://saturn.jpl.nasa.gov/news/events/huygensDescent/index.cfm">pictures</a>. This is awesome. <ul>Recommended: <li><a href="http://saturn.jpl.nasa.gov/home/index.cfm">Cassini-Huygens</a> </ul> <ul>To read: <li>Ralph Lorenz and Jacqueline Mitton, <cite>Lifting Titan's Veil: Exploring the Giant Moon of Saturn</cite> [Looks promising, but it's a 2002 book; surely it would be better to wait five or six years until Cassini has done its work?] <li>D. Schulze-Makuch and D. Grinspoon, "Biologically Enhanced Energy and Carbon Cycling on Titan?", <a href="http://arxiv.org/abs/physics/0501068">physics/0501068</a> <li>Melissa G. Trainer, Alexander A. Pavlov, H. Langley DeWitt, Jose L. Jimenez, Christopher P. McKay, Owen B. Toon, and Margaret A. Tolbert, "Organic haze on Titan and the early Earth", <a href="http://dx.doi.org/10.1073/pnas.0608561103 "><cite>Proceedings of the National Academy of Sciences</cite> <strong>103</strong> (2007): 18035--18042</a> </ul>