Cassini Probe Detects 'Plastic' on Saturn's Moon Titan

NASA scientists have detected the chemical propylene, a key component in household plastic products, on Saturn's moon Titan. The find marks the first time propylene has been found on any moon or planet other than Earth, NASA said. 

The Cassini spacecraft, which has been orbiting Saturn since 2004 , made the observations using its composite infrared spectrometer, a device that registers infrared light emitted from celestial bodies in a similar way to how our hands feel the warmth of a campfire. The probe can detect the heat signal emitted by certain chemicals, although isolating one out of a crowd can be difficult.

Although it is the first molecule to be discovered with Cassini's infrared spectrometer, NASA researchers are highly confident in their claim that propylene is present on Titan. Propylene, also called propene, is one of the most essential chemicals in the production of common plastic goods such as food storage containers, computer mice and car bumpers.

A scientific paper detailing the research is published in Monday's edition of Astrophysical Journal Letters.

"This chemical is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center. "That plastic container at the grocery store with the recycling code 5 on the bottom -- that's polypropylene."

The Cassini probe's find builds upon researcher done by the Voyager 1 spacecraft as it flew by Saturn and its moon Titan in 1980. Voyager detected a variety of hydrocarbons on Titan, including all the important members of the one- and two-carbon families and some members of the three-carbon family. But propylene was conspicuously absent from the Voyager research, even though propylene's molecular neighbors were detected.

Even as future chemical analysis of Titian from ground and space-based instruments over the decades continued to reveal more information about Titan's chemical composition, a solid confirmation of the presence of propylene remained illusive.

"This measurement was very difficult to make because propylene's weak signature is crowded by related chemicals with much stronger signals," said Goddard scientist Michael Flasar. "This success boosts our confidence that we will find still more chemicals long hidden in Titan's atmosphere."