Despite a lack of water, Saturn’s Titan could harbour life

6 Jul 2016

Images of Titan's hydrocarbon sea, Ligeia Mare, taken by the Cassini spacecraft. Image via NASA/JPL-Caltech/ASI/Cornell

We often think that water is the minimum requirement for life to occur on Earth, or any planet, for that matter, but new research suggests Saturn’s waterless moon, Titan, could still harbour life.

As the ringed planet’s largest moon, Titan has for many years remained a celestial object of fascination within our solar system, along with many other moons that have been analysed for potentially harbouring alien life.

However, at first glance, the planet’s rivers, lakes and rain of methane would suggest that its surface would be nothing but a desolate wasteland incapable of harbouring life.

Life outside the Goldilocks zone

Now, however, a team of researchers from Cornell University in the US has created a simulation that suggests Titan’s lack of water does not necessarily mean it couldn’t allow the development of microbial life.

While established science had for decades believed that life could only exist on a planet within a ‘Goldilocks zone’ where the sun is not too hot and liquid water could exist on the surface, increasing evidence suggests this is not the only situation.

Titan atmosphere

An infrared composite image of Titan from the Cassini spacecraft. Image via NASA

Publishing its findings in the journal Proceedings of the National Academy of Sciences, the team has said that its simulation was spurred on by the discovery of polymers such as polyimine, which suggests that something else is going on, on the planet’s surface.

After all, Titan is the only other location in the solar system where liquid erosion occurs during rainfall – albeit it methane rain – which led to the research team’s computer simulation determining that the planet’s cold atmosphere acts as an energy catalyst even with the meagre amounts of sunlight that come through its thick clouds.

Similar chemical composition to early Earth

Of particular interest to the team was the chemical hydrogen cyanide as, based on previous research, it has been suggested the chemical was crucial to the origin of life here on Earth due to its role in the development of proteins and DNA.

Hydrogen cyanide is one of the most abundant chemicals within Titan’s atmosphere, which could play into the development of polyimine on the moon, which could act as a catalyst for waterless life.

A new starting point for research

Speaking to Space.com, co-author of the research paper, Jonathan Lunine, said of Titan’s potential: “We are not saying we created Titan life in a computer, or even structures that might be in life on Titan.

“We are saying that the early steps toward structures, catalysis and absorption of energy might be possible on Titan with polymers like those we modelled.”

Based on these findings, the research team now hopes that, with this discovery of the role polyimine could play in the development of life on Titan, it will begin to look at the moon in greater detail from this new perspective.

Colm Gorey was a senior journalist with Silicon Republic

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