The highly successful Cassini/Huygens mission began sending data back to earth in the spring of 2005, and since that date man has documented volumes of data concerning this moon once a mystery to mankind. While Titan is uninhabitable by man, "Scientists believe that Titan's environment may be similar to that of the Earth's before life began putting oxygen into the atmosphere" (Hamilton). The image of a primordial earth has added to Titan's mystique as the Cassini orbiter continues to map and reveal the surface and composition of Saturn's moon, Titan.
Understanding the geophysical characteristics of Titan begins with a picture of its chemical composition and the temperature range that it exists in. The atmosphere of Titan, the only moon in the solar system to have a dense atmosphere, is composed primarily of nitrogen and methane (Ocean May Exist). There are also trace amounts of organic chemicals in the atmosphere, though the conditions are far from ideal for the creation of life. The moon has a gravitational force of about 15 percent of earth's and the temperature hovers around a cold minus 289 degrees Fahrenheit (Britt, "Smog on Saturn's Moon"). In 2002, scientists studying Titan believed that, "High in the Titan sky, solar radiation helps fuel chemical reactions that break the nitrogen and methane down into other substances. Eventually, lower down, some of these molecules serve as seeds for clouds. Methane condenses on the seeds to form rain or hailstones that fall to the surface" (Britt, "Smog on Saturn's Moon"). Indeed, three years later the Huygens probe would land during a methane rain as it broke through the atmosphere on Titan. These early and initial observations of Titan created more questions than they answered. What was the source of all the methane on the planet In a solar system that is routinely impacted by objects from space, why was Titan' surface relatively smooth, as if it had escaped the force of impacts The Cassini mission and the Huygens probe would provide the data necessary to begin to answer these questions.
Much of what we know about Titan came from a descent and landing on Titan's surface of the Huygens probe, a part of the European Space Agency's Cassini program. There has been a keen interest in Titan since the early days of astronomy as scientists speculated on a world that "is extraordinarily like Earth, with rivers, rain, islands, seas and mountains, but is otherwise a totally alien world where geology and chemistry are turned on their heads" (Walker). Launched in 1997, the Huygens probe separated from the Cassini orbiter and entered Titan's thick atmosphere in late 2004. Though it was not designed to be a lander, Huygens survived the descent and continued to relay data back to Earth for approximately 90 minutes. The first images sent back from Huygens were remarkable. According to Eddy, "Huygens landed at the shoreline of what appears to be large body of liquid when it ended a seven-year journey". Landing in a rain of methane, the Huygens probe landed in an area that was typical of Titan's surface. "European Space Agency scientists said at a press conference in Paris that the consistency of the surface was like icy wet mud" (Walker). The Cassini orbiter is still active and continues to survey the moon as it makes passes near Titan