Ethane lakes in a red haze: Titan’s uncanny moonscape

Titan’s ethane lakes in a red haze.

So far, there are no recognisable signs of organic life. That’s not surprising: by terrestrial standards, Titan is a deep freeze with surface temperatures at a chilly -180°C. Yet Titan is very much alive in the sense that its atmosphere and surface are changing before our eyes. Clouds drift through the haze and rain falls from them to erode stream-like channels draining into shallow lakes. Vast dune fields that look as if they were lifted from the Sahara sprawl along Titan’s equator, yet the dark grains resemble ground asphalt rather than sand. It is a bizarrely different world that looks eerily like home. Or as planetary scientist Ralph Lorenz puts it: “our prototype weird-world exoplanet”.

The basic ingredients of life might exist in Titan’s atmosphere

Big news! In a simulation of the upper atmosphere of Titan at about 600 miles altitude, scientists have discovered the basic ingredients of life are quickly synthesized when exposed to the kind of hard radiation found there. Key quote from the press release, issued today at the 42nd meeting of the AAS Division for Planetary Sciences:

The molecules discovered include the five nucleotide bases used by life on Earth (cytosine, adenine, thymine, guanine and uracil) and the two smallest amino acids, glycine and alanine.

For those who don’t remember their high school biology, these nucleotides are the building blocks of DNA.

The abstract of the scientist’s work can be found here.

What the scientists did was recreate the basic ingredients of Titan’s upper atmosphere, comprised of nitrogen, methane and carbon monoxide. Cassini data has shown that within this atmosphere are very large molecules, as yet unidentified.

The scientists then bathed their recreation in the kind of intense radiation expected at that altitude, and amazingly produced the complex organic molecules that are basic to life. Moreover, the experiment was the first to produce these complex molecules without the presence of water, something that scientists have previously thought was required. These results suggest that in addition to forming in the oceans, life could also form in the upper atmospheres of planets.

This result also suggests strongly that it is incredibly easy to produce the basic building blocks of life, almost anywhere in the universe where organic molecules are present.

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