Titan: Nasa scientists discover evidence 'that alien life exists on Saturn's moon'

Scientists have speculated that extra-terrestrial organisms might consume methane the way most life here on earth consumes oxygen or carbon dioxide. This might be the first evidence of that... If it turns out to be true, it will have gigantic implications into the range of possibilities for life in the universe and would imply that life is far more common than we once thought.

From the Telegraph.co.uk :

Researchers at the space agency believe they have discovered vital clues that appeared to indicate that primitive aliens could be living on the planet.

Data from Nasa's Cassini probe has analysed the complex chemistry on the surface of Titan, which experts say is the only moon around the planet to have a dense atmosphere. They have discovered that life forms have been breathing in the planet’s atmosphere and also feeding on its surface’s fuel.