Starship Asterisk*

Research by astrobiologist William Bains suggests that if life has evolved on the frozen surface of Saturn's moon, Titan, 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 13th April.

"Hollywood would have problems with these aliens" says Dr. Bains. "Beam one onto the Starship Enterprise and it would boil and then burst into flames, and the fumes would kill everyone in range. Even a tiny whiff of its breath would smell unbelievably horrible. But I think it is all the more interesting for that reason. Wouldn't it be sad if the most alien things we found in the galaxy were just like us, but blue and with tails?"

If life does exist on Saturn's intriguing moon Titan, it probably stinks.

The icy moon has long been seen as a potential spot for extraterrestrial life, but so far, there's no evidence of any living things there.

And if there were life on Titan, it would likely involve chemicals that are noxious and disgusting to humans, scientists say.
...
For example, Titan life's metabolism might involve chemical compounds such as phosphine and hydrogen sulfide, which are both foul-smelling gases that are toxic to humans.

New discoveries have a way of messing with old definitions. Take, for example, the concept of a habitable world.

The standard definition of a “habitable world” is a world with liquid water at its surface; the “habitable zone” around a star is defined as that Goldilocks region – not too hot, not too cold - where a watery planet or moon can exist.

And then there’s Titan. Saturn’s giant moon Titan lies about as far from the standard definition of habitable as one can get. The temperature at its surface hovers around 94 degrees Kelvin (minus 179 C, or minus 290 F). At that temperature, water is a rock as hard as granite.

And yet many scientists now believe life may have found a way to take hold on Titan. Water may all be frozen solid, but methane and ethane are liquids. In the past few years, instruments on NASA’s Cassini spacecraft and images captured by ESA’s Huygens probe have revealed an astonishing world with a complete liquid cycle, much like the hydrologic cycle on Earth, but based on methane and ethane rather than on water.

Scientist find life in a lake of asphalt that is the closest thing on Earth to the hydrocarbon seas on Titan.

Pitch Lake is a poisonous, foul smelling, hell hole on the Caribbean island of Trinidad and Tobago. The lake is filled with hot asphalt and bubbling with noxious hydrocarbon gases and carbon dioxide. Water is scarce here and certainly below the levels normally thought of as a threshold for life.

These alien conditions have made Pitch Lake a place of more than passing interest to astrobiologists. Various scientists have suggested that it is the closest thing on Earth to the kind of hydrocarbon lakes that we can see on Saturn's moon Titan. Naturally, these scientists would very much like to answer the question of what kind of life these places can support.

• arXiv.org > q-bio > arXiv:1004.2047 > 12 Apr 2010