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Titan was discovered by Dutch astronomer Christiaan Huygens on March 25, 1655. It was named by John Herschel (son of William Herschel, discoverer of Mimas and Enceladus) after the mythological Titans who were the brothers and sisters of Cronus, the Greek Saturn. In Greek mythology, the race of powerful deities that ruled during the legendary Golden age.
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Many probes have imaged Titan, however only one has landed - the Huygens Lander. It visited on January 14, 2005 and this visit was the most distant landing of any mission in the Solar System.
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Titan is mainly composed of rocky core, surrounded by layers of water ice. It is likely the core is still hot, with a layer of liquid water and ammonia. Its surface has liquid hydrocarbon lakes and the vents of cryovolcanoes, distributed among areas of dark and bright terrain with few impact craters. Also, tectonic forces, which is movement of the ground due to pressures beneath, appear to exist on Titan.
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Xanadu is a highly reflective area on the leading hemisphere of Titan that is 2,400 kilometers, about the size of Australia. This feature was identified in 1994 by astronomers using the Hubble Space Telescope at infrared wavelengths. Radar images taken on the Cassini mission revealed dunes, hills, valleys and rivers were present on Xanadu. These features are likely carved in water ice by liquid methane and ethane. Water ice behaves similarly to rock that temperatures and pressures present on the surface of Titan.
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Scientists believe that conditions on the moon are similar to Earth's early years, with the exception that Earth has always been warmer since it is closer to the Sun.
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The surface temperature is minus 290 degrees Fahrenheit (minus 179 degrees Celsius), which allows methane to be found in its liquid form and makes water as hard as rocks. Titan receives about 1% as much sunlight as Earth, but then before it reaches the surface, around 90% of that sunlight has been absorbed by the thick atmosphere.
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The surface pressure is slightly higher than Earth's pressure. The pressure at sea level is 1 bar while Titan's is 1.6 bars.
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Titan orbits Saturn at a distance of about 759,000 miles (1.2 million kilometers), which takes 15 days and 22 hours to complete a full orbit. It is tidally locked like other moons around their primary planet, so it has a rotation period that is the same as its orbital period. That means it orbits Saturn in the same length of time that it turns on its axis.
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Titan may have formed as material in orbit around early Saturn began to accrete. Collisions and impacts may have disturbed the orbits of Titan and other moons into their current positions.
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