Titan is the largest moon of Saturn, and the second largest moon in the entire Solar System (Jupiter's moon Ganymede is the largest). Titan's diameter is 5,150 km (3,200 miles), which is comparable to the distance across the United States. It is considerably larger than Earth's moon, and is even larger than two planets - Mercury and Pluto. Titan orbits Saturn at a distance of 1,221,830 km (759,208 miles).

Titan has a dense atmosphere, which, like Earth's atmosphere, is composed mostly of nitrogen. It is the only moon in the Solar System possessing a substantial atmosphere. Atmospheric pressure at the surface of Titan is about 60% greater than the pressure at sea level on Earth! Titan's atmosphere also contains a fair amount of methane, as well as smaller quantities of various hydrocarbons created via the exposure of methane to solar ultraviolet radiation. A smog-like haze in Titan's atmosphere prevents us from directly observing the moon's surface in visible wavelengths from Earth or orbiting spacecraft.

Titan's surface is quite cold, with temperatures hovering around -178º C (-288º F). The European Space Agency's Huygens probe, which landed on the icy moon in January 2005, has given us our first good look at the surface of Titan. NASA's Cassini spacecraft is also revealing details of the moon's surface via radar. Titan's surface may have areas covered by lakes or seas of liquid methane or ethane!

Titan was discovered by the Dutch astronomer Christiaan Huygens in 1655. Modern scientists are especially interested in Titan because of its unusual history and complex atmospheric chemistry. Some scientists think conditions on Titan may be similar to those on Earth shortly before life arose on our planet, making Titan a modern laboratory for studying the primordial Earth.

Titan is the largest moon of the planet Saturn. Titan is the second largest moon in our Solar System. The diameter of Titan is 5,150 km (3,200 miles), which is about the distance across the United States. Jupiter's moon Ganymede is the only moon in our Solar System that is larger than Titan. Titan is larger than the planets Mercury and Pluto!

Titan is the only moon in the Solar System that has a thick atmosphere. Titan's atmosphere is even thicker than Earth's! We can't see through Titan's atmosphere to get a clear view of the moon's surface. Thanks to the Huygens lander and to radar on the Cassini spacecraft we are beginning to get some good looks at the surface of Titan.

Titan was discovered by Christiaan Huygens in 1655. It orbits Saturn at a distance of 1,221,830 km (759,208 miles). Titan is very cold (-178º C, or -288º F, at the surface), and is mostly made of ice. The moon has an unusual history, and some scientists believe there is a very tiny chance that life might exist on Titan!

Titan is a moon of the planet Saturn. It is Saturn's largest moon. Titan is the second largest moon in the whole Solar System. It is larger than Earth's moon. It is even larger than two planets - Mercury and Pluto!

Titan has an atmosphere. Most moons don't. Titan's atmosphere is much thicker than the atmosphere of any other moon. It is even thicker than Earth's atmosphere.

The air on Titan is orange! We can't see through Titan's air, so we don't know much about the surface of Titan. We are starting to find out a little about Titan's surface, though. A robot spaceship named Huygens landed on Titan in January 2005. Huygens took some pictures of Titan's surface. Another robot spaceship, named Cassini, is taking pictures of Titan from space.

Some scientists think there is a tiny chance that life exists on Titan. Other scientists think that Titan is too cold for life. Titan is mostly made of ice. The moon has a strange history.

Titan was discovered by a Dutch astronomer named Christiaan Huygens. Huygens discovered Titan in 1655.