One of Saturn’s satellites, Titan, is the only moon in the Solar System to have a substantial atmosphere. It is covered in thick clouds, and scientists believe conditions beneath these clouds may be similar to those on Earth billions of years ago. Although temperatures on the planet are believed to be well below freezing level, some scientists believe that internal heating may allow areas of liquid water to exist on the moon’s surface. Some believe that primitive life may even exist on the moon. The European Space Agency’s Huygens probe has been designed to parachute down through Titan’s atmosphere in order to investigate the moon at first hand (right).
An orange haze surrounding Titan kept its surface a mystery for Earth’s scientists until the arrival of the Cassini mission in 2004. Titan’s atmosphere extends about 370 miles high (about 600 kilometers), which makes it a lot higher than Earth’s atmosphere. Because the atmosphere is so high, Titan was thought to be the largest moon in the solar system for a long time. It wasn’t until 1980 that Voyager was close enough to discover it was actually smaller than Ganymede.
Titan’s atmosphere is active and complex, and it is mainly composed of nitrogen (95 percent) and methane (5 percent). Titan also has a presence of organic molecules that contain carbon and hydrogen, and that often include oxygen and other elements similar to what is found in Earth’s atmosphere and that are essential for life.
There is an unsolved mystery surrounding Titan’s atmosphere: Because methane is broken down by sunlight, scientists believe there is another source that replenishes what is lost. One potential source of methane is volcanic activity, but this has yet to be confirmed.
Titan’s atmosphere may escape to space in a similar way that Earth’s atmosphere does. The Cassini spacecraft has detected polar winds that draw methane and nitrogen (charged with interactions with light) out along Saturn’s magnetic field and out of the atmosphere. A similar process is believed to happen on Earth with our own magnetic field.
“At Saturn’s largest moon, Titan, Cassini and Huygens showed us one of the most Earth-like worlds we’ve ever encountered, with weather, climate and geology that provide new ways to understand our home planet.
Picture Credit : Google
