A new recipe created in a NASA laboratory has re-created the composition of the atmosphere on Titan -- the largest moon orbiting the planet Saturn -- and in the process managed to classify a previously unidentified material in the moon's atmosphere spotted by Cassini's Composite Infrared Spectrometer.
To re-create the atmosphere, NASA scientists combined a number of different gases in a chamber and let them react with each other. With the correct gases and the correct conditions, the idea is that those reactions should produce the same materials found in the moon's atmosphere.
Although the scientists knew something about Titan's atmosphere -- for example, that the two most plentiful gases are nitrogen and methane -- the exact proportions and other materials are unknown. Previous experiments yielded nothing that matched the spectral signature seen by Cassini.
It was when the researchers added a third gas -- benzene, another identified component of Titan's atmosphere -- that the mixture started to take shape. They then extrapolated which other gases are likely to be present based on the presence of benzene: closely related hydrocarbons known as aromatics.
When an aromatic containing nitrogen was added to the recipe, the spectral features matched up well with the distinctive spectral signature captured by Cassini. It's the closest anyone has come to date to re-creating the moon's atmosphere.
"Now we can say that this material has a strong aromatic character, which helps us understand more about the complex mixture of molecules that makes up Titan's haze," said planetary scientist Melissa Trainer.
The recipe isn't yet perfect, and NASA's next step is to continue to tweak it until it's as close as it can possibly get to Cassini's spectrometer data. Alas, no one from NASA has actually described the smell -- but it's probably not a healthy idea for a human to take a big whiff of that particular chemical cocktail.