Introduction
Titan is the largest and brightest moon of Saturn with a radius of 2575 km. It was discovered in 1655 by the Dutch astronomer Christiaan Huygens. Titan is named after the Greek family of Giants, who are children of Gaia (Earth) and Ouranos (Heaven). Some of his sister moons are named after the family members of the Titans.
Titan is rotating at a distance of 20.3 Saturn radii (1 226 000 km) around Saturn. A rotation around Saturn takes about 16 Earth days, a rotation around the Sun about 30 Earth years. Since the rotation period almost equals the orbital period, Titan always shows the same side to Saturn.
Titan is the only planetary moon with a substantial atmosphere. There are many similarities with the Earth's atmosphere. In both atmospheres molecular nitrogen is the main constituent and the surface pressure is of the order of 1 bar. Several other trace gases such as methane, hydrogen, carbon monoxide and several organic molecules are detected.
In 1980 Titan was observed closer by Voyager 1 which also sent the first colour images of Titan to the Earth. Voyager 1 found that Titan carries the national colour of his Dutch discoverer Huygens: orange. This colour is the result of the thick stratospheric organic haze layer. This thick haze layer covers the whole moon, and made an observation of the surface in the visible spectrum difficult. Consequently, many speculations about the characteristics of the surface emerged, which ranged from a global ethane ocean to a dry rock surface.
The Cassini/Huygens mission, which was successfully launched on 15 October 1997 and is investigating Titan since 2004, revolutionized our view of Titan.
On the following pages we invite you to visit the fascinating world of Titan that is being investigated by us and the Cassini/Huygens mission.
Image credit: NASA/JPL
Physical Parameters of Titan:
Mean Distance from the Sun Mean Distance from Saturn Rotation Period Orbital Period around Saturn Orbital Period around the Sun Obliquity Eccentricity around Saturn Eccentricity around the Sun Mean Orbital Velocity Equatorial Radius | 9.564 AU = 1 428 000 000 km 1 226 000 km = 20.3 Saturn radii 15.95 days 15.95 days 29.5 years 26.7 degrees 0.0292 0.056 5.57 km/s 2 575 km |
| Background Magnetic Field of Saturn | 5 nT |
Surface Gravity Acceleration Surface Temperature Surface Pressure Atmospheric Composition | 1.35 m/s2 91-94 K 1 467 hPa >95 % N2,CH4,N,H,H2,... |