<p><b>MODEL OF TITAN'S ATMOSPHERE</b>
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<ul><li>Titan presents an environment that appears to be unique in the solar system, with a thick, hazy atmosphere containing organic (or carbon-based) compounds, an organic ocean or lakes, and a rich soil filled with frozen molecules similar to what scientists believe led to the origin of life on Earth. The major differences between Titan and Earth are Titan's absence very low temperatures and an absence of liquid water. Scientists believe that the surface temperatures on Titan are cold enough to preclude any biological activity whatsoever at Titan.</li></ul><p>As on Earth, the dominant atmospheric constituent in Titan's atmosphere is nitrogen. Methane represents about six percent of the atmosphere. Titan's surface pressure is 1.6 times that on Earth, despite Titan's smaller size. The surface temperature was found by Voyager to be 95 degrees Kelvin (minus 289 degrees Fahrenheit).
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The opacity of Titan's atmosphere is caused by naturally produced photochemical smog. Voyager's infrared spectrometer detected many minor constituents produced primarily by photochemistry of methane, which produces hydrocarbons such as ethane, acetylene and propane. With Titan's smoggy sky and distance from the Sun, a person standing on Titan's surface in the daytime would experience a level of daylight equivalent to about 1/1,000th the daylight at Earth's surface.
NASA/JPL
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