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Line 31: − − Until 2005, Titan was regarded as the only natural satellite in the [[solar system]] to have a true [[atmosphere]]. But the [[Cassini-Huygens mission]] has already demonstrated that Saturn's inner moon [[Enceladus]] ''also'' has an atmosphere, believed composed of ionized [[water]] vapor from repeated eruptions from [[volcano]]es and/or [[geyser]]s on its surface. This "atmosphere" is constantly escaping from Enceladus, perhaps to persist as the E ring of Saturn's ring system. Thus it requires a continuous source of replenishment. The theories of Enceladus' volcanic and/or geothermal activity are an attempt to explain this replenishment.<ref name=encelatm>"[http://www.esa.int/SPECIALS/Cassini-Huygens/SEM9RC2IU7E_0.html Cassini finds atmosphere on Enceladus]." ''ESA Cassini-Huygens, March 16, 2005. Accessed February 16, 2008.</ref> Line 138:
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| albedo=0.21<ref name=ssdphys/>
| albedo=0.21<ref name=ssdphys/>
}}'''Titan''' ([[Greek]] Τῑτάν first-generation god) is the largest [[satellite]] of [[Saturn]], the second-largest planetary satellite in the [[solar system]] (after [[Ganymede]]), and the only body other than [[Earth]] to have bodies of liquid on its surface for any length of time. Titan is twentieth in order from Saturn and the sixth satellite of [[dwarf planet]] size (consistent with its official [[International Astronomical Union|IAU]] catalog designation as "Saturn VI").
}}'''Titan''' ([[Greek]] Τῑτάν first-generation god) is the largest [[satellite]] of [[Saturn]], the second-largest planetary satellite in the [[solar system]] (after [[Ganymede]]), and the only body other than [[Earth]] to have bodies of liquid on its surface for any length of time. Titan is twentieth in order from Saturn and the sixth satellite of [[dwarf planet]] size (consistent with its official [[International Astronomical Union|IAU]] catalog designation as "Saturn VI").
The most exciting finds on Titan to date are the liquid hydrocarbon "seas," containing among them more hydrocarbons than the entire proved reserves of [[oil]] and [[natural gas]] on earth.<ref name=Corsi>Corsi, Jerome R. "[http://www.worldnetdaily.com/index.php?fa=PAGE.view&pageId=56480 New data: Maybe oil isn't from dead dinos]." ''WorldNetDaily'', February 15, 2008. Accessed February 16, 2008.</ref>
The most exciting finds on Titan to date are the liquid hydrocarbon "seas," containing among them more hydrocarbons than the entire proved reserves of [[oil]] and [[natural gas]] on earth.<ref name=Corsi>Corsi, Jerome R. "[http://www.worldnetdaily.com/index.php?fa=PAGE.view&pageId=56480 New data: Maybe oil isn't from dead dinos]." ''WorldNetDaily'', February 15, 2008. Accessed February 16, 2008.</ref>
The atmosphere is not of uniform composition. Clouds, presumably of methane, do form. Furthermore, Huygens' images of the surface show clear signs of erosion and formations that look like dry riverbeds, a sign that rain occurs--though the rain is of methane, not water.<ref name=Arnett/> However, the data do ''not'' indicate the looked-for "ocean" of methane, but rather indicate something akin to the seasonal rivers and lakes seen on earth.<ref name=Arnett/><ref name=HuygensFindings/>
The atmosphere is not of uniform composition. Clouds, presumably of methane, do form. Furthermore, Huygens' images of the surface show clear signs of erosion and formations that look like dry riverbeds, a sign that rain occurs--though the rain is of methane, not water.<ref name=Arnett/> However, the data do ''not'' indicate the looked-for "ocean" of methane, but rather indicate something akin to the seasonal rivers and lakes seen on earth.<ref name=Arnett/><ref name=HuygensFindings/>
Until 2005, Titan was regarded as the only natural satellite in the [[solar system]] to have a true [[atmosphere]]. But the [[Cassini-Huygens mission]] has already demonstrated that Saturn's inner moon [[Enceladus]] ''also'' has an atmosphere, believed composed of ionized [[water]] vapor from repeated eruptions from [[volcano]]es and/or [[geyser]]s on its surface. This "atmosphere" is constantly escaping from Enceladus, perhaps to persist as the E ring of Saturn's ring system. Thus it requires a continuous source of replenishment. The theories of Enceladus' volcanic and/or geothermal activity are an attempt to explain this replenishment.<ref name=encelatm>"[http://www.esa.int/SPECIALS/Cassini-Huygens/SEM9RC2IU7E_0.html Cassini finds atmosphere on Enceladus]." ''ESA Cassini-Huygens, March 16, 2005. Accessed February 16, 2008.</ref>
== The Prebiotic-Abiotic Controversy ==
== The Prebiotic-Abiotic Controversy ==
Huygens was designed to land, and to study the atmosphere and the surface in detail on the way down. Huygens landed fully functional on Titan on January 14, 2005. It remained functional for three hours while it sent back many images and much data on the composition, including the carbon-isotopic ratio, of the Titanian atmosphere.
Huygens was designed to land, and to study the atmosphere and the surface in detail on the way down. Huygens landed fully functional on Titan on January 14, 2005. It remained functional for three hours while it sent back many images and much data on the composition, including the carbon-isotopic ratio, of the Titanian atmosphere.
Cassini continues to study Titan and the rest of the Saturnine system. Its mission was originally scheduled to run for four years, ending in July 2008, but NASA has announced a two-year extension with multiple rendezvous with Titan and additional rendezvous with [[Enceladus]], [[Rhea]], [[Dione]], and [[Helene]]. Mission planners also suggest that after two years, Cassini might still have enough fuel for another two-year extension, and speak hopefully of specific future missions to Titan and Enceladus.<ref name=extended>Brown, Dwayne, and Martinez, Carolina. "[http://www.nasa.gov/mission_pages/cassini/media/cassini-20080415.html NASA Extends Cassini's Grand Tour of Saturn]." [[National Aeronautics and Space Administration|NASA]], April 15, 2008. Accessed May 16, 2008.</ref>
== In fiction ==
== In fiction ==