10 Places Most Likely To Harbour Alien Life

Titan - Saturn's largest moon - might be a good candidate for life due to the fact that it has a thick, chemically active atmosphere, liquid lakes and a relatively Earth-like weather system.

As far as we know, life requires some shielding from the solar radiation of outer space, much like our atmosphere, and Titan's thick atmosphere would afford such protection to any life on its surface.

The only issue we have with Titan is that, despite its lovely thick atmosphere, the chemical make up of this atmosphere is very different to our own. This, and the fact that the moon is much colder than the Earth, is the reason why Titan was disregarded for a long time as a potential candidate for extraterrestrial life, but some scientitst think that we may have been too quick to reject it.

The surface temperature of Titan is around -179°C, far too cold for liquid water to be present, but it does have large lakes of liquid methane and ethane that are saturated with hydrocarbons - i.e. the building blocks of life.

If we did find that Titan harbours life, it would completely rewrite what we know about the conditions under which life can form. If life were to exist on Titan, it would differ from life on Earth in some subtly different ways, probably breathing in hydrogen instead of oxygen and exhaling methane instead of carbon dioxide. It might also burn acetylene for energy instead of glucose like we do.

There has been some talk flying around of sending a lander probe to go and take a closer look at Titan, but so far nothing has been confirmed.