NASA is figuring out the flavors of Saturn's moon Titan, cooking up an artificial atmosphere here on Earth to try to replicate the distinctive smog surrounding the yellowed body. The mystery gases surrounding Saturn's largest moon had been stumping researchers, unable to combine the likely mixture of nitrogen and methane that led to the exact spectrometer readings taken by the Cassini spacecraft surveying Titan.
One of the instruments Cassini carries is a Composite Infrared Spectrometer, which can be used to figure out the so-called spectral signature of the molecule mixture present in a volume of gases. By trying to mix a similar cloud and get the same results from it, scientists can work their way back to figuring out what, exactly, Titan's atmosphere comprises.
That's the theory, anyway; in practice it turned out to be somewhat tougher. Although broadly known to be a combination of hydrocarbons and nitriles, the range of possibilities in both of those categories is vast.
All of the attempts at a probably mix failed to match, however, until NASA's scientists added in a third type of gas. Known as aromatics - though not necessarily fragranced to the human nose - the hydrocarbon sub-category brought the tests to the closest to what Cassini recorded so far.
There's still some work to be done, though. Although the researchers have identified nitrogen-based aromatics as producing the most similar results to Titan, they're still not down to an exact match.
Future work will try to identify which of the polycyclic aromatic nitrogen heterocycles is the most probable.