A stinking, poisonous lake filled with carbon dioxide and hydrocarbons might not seem like the kind of place for living things to thrive, but researchers have discovered life in Trinidad’s Pitch Lake, a hot asphalt lake teeming with all kinds of noxious gases and containing very little water. But the discovery isn’t just of interest to biologists; Pitch Lake is thought to be the closest thing we have on Earth to the hydrocarbon lakes on Saturn’s Titan moon. And if microbial life can survive in Pitch Lake, it might be able to thrive on Titan’s hostile surface.

The tiny single-celled life forms in Pitch Lake are highly unique and very hardy, mostly archea and bacteria that can survive in an oxygen-free atmosphere. They feed off hydrocarbons, breathe metals and require very little water. Basically, they’re unlike almost every other living thing on Earth (similar organisms have been found in subsea oil wells) and their existence in Pitch Lake challenges widely accepted notions: that Titan is too harsh an environment to harbor life as we know it, and that liquid water is necessary for the proliferation of life.

Of course, finding life in a Titan-like lake and finding life on Titan are two completely different things. For one, it’s not clear how much water the Pitch Lake organisms require, and it’s altogether possible that they cluster in areas where water content is high. There is an abundance of other variables in play as well: temperature, sunlight, the precise chemical makeup of Pitch Lake versus Titan’s hydrocarbon lakes, etc. So there’s still plenty to be proved out in this case.

Nonetheless, the fact that the Pitch Lake microorganisms exist at all does further prove that life is persistent, and the ingredients for a habitable space may yet be different than many of us think. Titan contains plenty of carbon and a fluctuating, diverse environment, and that may just be enough to sustain life, albeit a very tiny, very unique brand of it.

Technology Review