Titan is a cold world with methane lakes and a dense orange atmosphere. But beneath the icy crust, warm puddles may hide, formed after meteorite impacts. In such a puddle, like a chemical flask the size of Selk Crater, simple gases from the air, hydrogen cyanide and acetylene, mix. Add ammonia, and you get a broth where future components of living cells simmer.

Calculations showed that at 1% ammonia, short fatty acids and ribose, the backbone of RNA, form best. At 2% ammonia, the peak shifts to longer fatty acid chains. Interestingly, the ratio of pyrimidines to purines, and the smooth decrease of fatty acids with chain length, resembles the pattern seen in meteorites — chunks of ancient material that fell to Earth. This suggests the chemistry in Selk Crater might mirror what went on in the early solar system.

The Dragonfly probe, equipped with a mass spectrometer, could test these predictions right on the spot. If samples reveal a mixture of molecules similar to the calculated one, it would point to a past watery environment and the amount of ammonia. If the picture turns out different, we might stumble upon signs of something unusual.