Life on Titan may be smelly and explosive
Scientists have yet to find life beyond the confines of Earth but Saturn's largest moon Titan is becoming the focus of increased interest.
However if life were to be found锛?it would not be life as we know it. A commonly held belief is that life could only evolve on worlds where water is prevalent. But some scientists suggest Titan may be an exception to that rule.
Although nothing has yet been found to suggest life on Titan, research by astrobiologist William Bains suggests that if life has evolved on the frozen surface of Saturn's moon it would be strange, smelly and explosive compared to life on Earth. Dr Bains will present his work at the National Astronomy Meeting in Glasgow on Tuesday April 13th.
"Life needs a liquid; even the driest desert plant on Earth needs water for its metabolism to work," Bains says, "So, if life were to exist on Titan, it must have blood based on liquid methane, not water. That means its whole chemistry is radically different. The molecules must be made of a wider variety of elements than we use, but put together in smaller molecules. It would also be much more chemically reactive."
Titan is, in many ways, the closest object in the solar system to Earth itself. It has an atmosphere which is so thick that it obscures the moon钬檚 surface in a perpetual orange haze. It has rain, rivers, and lakes, making it the only other world in the solar system known to have liquid on its surface. And it钬檚 clouds and seas are thick with hydrocarbons, the building blocks that, when combined, formed life on Earth.
However, the temperature on the surface is -180 degrees Celsius. Water is permanently frozen into ice and the only liquid available is liquid methane and ethane, which the Cassini/Huygens mission has shown is present in ponds and lakes on the surface of the moon.