Collaborating with a group of Spanish Astronomers, members of the Astrophysics and Astrochemistry Laboratory group found strong evidence for the presence of polycyclic aromatic hydrocarbon (PAH) molecules in the atmosphere of Saturn’s largest moon, Titan. Utilizing the wealth of PAH spectra available in the NASA Ames PAH IR Spectroscopic Database, they analyzed data obtained by NASA’s spacecraft Cassini.
Long time a mystery, the haze making up Titan’s atmosphere can finally, at least in part, be attributed to PAHs. Focussing on the 3 micron region, dominated by a strong methane feature, the team found unexplained substructure. After careful subtraction of the methane emission, a residual component peaking at 3.28 micron remained – indicative for the presence of aromatic material. Turning to the NASA Ames PAH IR Spectroscopic Database and after taking appropriate solar illumination into account, a blind computational analyzes was able to reproduce the observed emission feature and provide additional insight into the molecular properties of the emitting PAH mixture.
Titan is considered an early Earth analog and as such the presence of PAHs might provide important insight into the chemistry of the formation of life on our own planet.
The Spanish led group published there results in a paper that recently appeared in The Astrophysical Journal. Simultaneously, ESA and NASA issued a press release highlighting the results.
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