Man has always searched for his counterparts on other planets, in his solar system as well as beyond it. Initially, Mars was considered to carry signs and possibilities of extra-terrestrial life but now, reports suggest that many other celestial objects have a possibility to sustain life. The most promising amongst these is Titan, the biggest moon of Saturn. Ever since it was discovered by Christian Huygens in 1655, it has been the topic of great interest. This interest reached its peak when in January 2005, Huygen probe landed on the surface of Titan. Camera pictures by Huygen show drainage channels leading into a dark lake or sea.Titan is the only celestial body in our solar system other than Earth, which has a liquid flowing on its surface. This may be either liquid methane or ethane. The atmosphere of Titan is rich in organic compounds. This dense atmosphere contains mostly nitrogen, methane and some quantity of organic compounds. Organic compounds form when sunlight destroys methane. Hence, if sunlight is continuously destroying methane, how is methane getting into the atmosphere? On earth, it is life that refreshes the methane supply. Methane is the by-product of metabolism of many organisms and this methane replaces that destroyed by oxidation. The big question is, where is this methane coming from into the atmosphere of Titan? Well, it is observation that suggests possibilities of life on Tiitan.
The only factor going against the prospects of existence of some kind of life forms is that the temperature on this moon is extremely low. The temperature is as low as -180 degree C, far too cold for water to exist as a liquid. As per one theory, a colliding meteorite could have provided enough heat to liquefy heat for a few hundred years and life might have been possible for those few years. The theory is convincing indeed, but as for now, the temperature of Titan is too low for life to evolve and sustain. Scientists believe that in the later stages of our sun, it will grow bigger and hotter and temperature levels will rise; soon enough, at this stage, it may expand to a level when it will actually come very near to Titan, and increase its temperature. But in the process of expansion, it will swallow up our Earth. So, ironically, if at all there is to be any life on Titan, it will be at our cost!
Scope for discoveries and knowledge is the closest thing to infinity. We may or may not find extra-terrestrial life. But, we can not satisfy our thirst to know about our possible friends or enemies in the outer space, by watching alien movies and reading ET novels. All we can do is try, and keep trying to find out if we are being watched.
[Image Source: http://www.flickr.com/photos/tailspin_tommy/2144726322/]