The list of organic molecules to be found in space grows annually. Now NASA's Cassini probe has spotted the chemical signature of propylene on Saturn's moon Titan. Much of the media talked of this small molecule being an ingredient of plastic, which it is in the sense that it is the monomer for producing polypropylene, but of course, the discovery is much more subtle. Infrared spectroscopy revealed the presence of this small molecule and details are published in Astrophysical Journal Letters. Titan's atmosphere is rich in nitrogen and the simplest hydrocarbon methane. Solar energy, however, can form reactive species that recombine to form ethane, propane and now we know propylene. But, Cassini's plasma spectrometer has revealed that there are hydrocarbons present with masses of many thousands of Daltons.