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The haze surrounding Titan's thick atmosphere appears purple in this Cassini image.
Cassini captured a purple haze encircling Titan's moon in 2004.
Saturn: Moons: Titan

Discovered in 1655 by the Dutch astronomer Christiaan Huygens, Titan is the biggest of the 46 known moons orbiting Saturn. It is a cold world enclosed by a thick, hazy atmosphere impenetrable by telescopes and cameras.

With an equatorial radius of 2,575 kilometers (1,600 miles), Titan is the second largest moon in our solar system. It's bigger than our own moon and even the planet Mercury. Only Jupiter's moon Ganymede is larger than Titan, with a diameter barely 112 kilometers (62 miles) greater.

The temperature at Titan's surface is about minus 178°C (minus 289°F).

Titan orbits Saturn at a distance of about 1.2 million kilometers (745,000 miles), taking almost 16 days to complete a full orbit - 15.94 days to be exact.

Titan is of great interest to scientists because it is the only moon in the solar system known to have clouds and a mysterious, thick, planet-like atmosphere. In 1980, NASA's Voyager 1 spacecraft tried to take close up images of the natural features of Titan's landscape but was unable to penetrate the thick clouds. Instead, the images showed only slight color and brightness variations in the atmosphere. Titan's atmospheric pressure is about 60 percent greater than Earth's - roughly the same pressure found at the bottom of a swimming pool.

Telescope Image of Titan
Titan's Continent
In 1994, NASA's Hubble Space Telescope recorded pictures of Titan, which suggested that a huge bright "continent" exists on the hemisphere that faces forward in orbit. These Hubble results don't prove that liquid "seas" exist, however; only that Titan has large bright and dark regions on its surface.

NASA's Cassini-Huygens spacecraft (currently orbiting Saturn) should shed new light on Titan's mysteries. The spacecraft's instruments are designed to reveal many of Titan's characteristics. During dozens of flybys, the Cassini orbiter will map Titan with cloud-penetrating radar and collect atmospheric data. The Huygens probe will dive through Titan's dense atmosphere with instruments capable of analyzing its components.

Combined with the "big picture" information that the Cassini orbiter will collect during Titan flybys, data from the Huygens probe will provide scientists with critical information that may shed light on ancient questions such as "Where did we come from?" And, "How did the planets form?"

Because of the extremely cold temperatures typical of celestial bodies that are that far away from the Sun, the structure of Titan's chemical atmosphere is in a state of deep freeze. It is this chemical composition that interests scientists a great deal because Titan's atmosphere might consist of compounds similar to those present in the primordial days of the Earth's atmosphere. Titan's thick cloudy atmosphere is mostly nitrogen, like Earth's, but may contain much higher percentages of "smog-like" chemicals such as methane and ethane. The smog may be so thick that it actually rains "gasoline-like" liquids. The organic nature of some of the chemicals found in Titan's atmosphere might indicate that this fascinating moon could harbor some form of life.

Titan in Mythology
A generic name for the children of Ouranos and Gaia. In the Orphic version, the Titans are the ancestors of the human race. The Titans devoured the limbs of Dionysus, the son of Zeus, who intended the child to have dominion over the world. Enraged, Zeus struck the Titans with lightning. The fire burned them to ashes, and from the ashes man was formed.
Just the Facts
Distance from Saturn: 
1,221,830 km
Equatorial Radius: 
2,575 km
134,550,000,000,000,000,000,000 kg
Saturn's Moons
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Last Updated: 02.28.05