Titan is the largest moon of Saturn and is the second largest in the solar system (the largest is Jupiter's Ganymede). An interesting fact is that Titan is larger than Pluto and Mercury but is still classified as a moon. It also has planet-like characteristics including a thick atmosphere with a pressure of 1.6 bars (60 percent greater than Earth's). The atmosphere is made rimarily of nitrogen with chemicals that cause the moon to appear orange.
Titan has a surface temperature of about -178°C (-289°F). The surface probably has large amounts of ethane exist below the atmosphere. This is then converted to acetylene, ethylene, and (in conjunction with nitrogen) hydrogen cyanide through a photochemical processes.
During the Voyager mission, it was xpected that Titan has a very interesting surface and that it had an atmosphere. Well the atmosphere was there alright, but so thick and opaque that the Voyager, who had been programmed to take many close-up photos of the moon only ended up with bunch of pictures showing almost nothing. However, the Cassini spacecraft (launched in October 1997) will answer many questions that scientists have had about Titan's surface (past the thick atmosphere). The spacecraft is expected to reach Saturn in June 2004. Small probes known as the Huygens probe will be sent to enter Titan's atmosphere and observe the surface up close.
Titan 
