By peering into the hydrocarbon haze of Saturn’s moon Titan, NASA’s Cassini spacecraft has made the first off-world detection of a molecule called propylene, one of the most important starting products of the modern plastic industry.

Propylene, also known as propene, is one of the simplest organic compounds, made from a chain of three carbons. On Earth, it is a byproduct of oil refining and other fossil fuel extraction processes. Humans use it as a raw material in creating many of the products in our world, including films, storage containers, and car bumpers. The molecule is also created naturally by some tree species and given off as a combustion product in forest fires.

Cassini detected propylene using its infrared spectrometer. Finding the molecule wasn’t too surprising — Titan is full of many different hydrocarbons including methane and propane — but spotting propylene has thus far eluded scientists. Previous missions had found other organic molecules with a three-carbon backbone, yet propylene was missing. Since it’s the lightest and simplest of this chemical family, its non-existence on Titan was perplexing. Researchers used Cassini’s data to sift through the hydrocarbon noise and finally extract propylene’s relatively weak signal. Their results appear today in the Astrophysical Journal Letters.

The finding highlights the alien chemistry of Saturn’s giant moon. Titan is a weird and wet world much like our own, except that hydrocarbon rain falls into ethane seas instead of water. Scientists have long wanted to explore such bodies with a boat-like probe but are thwarted by NASA’s plunging budget and the expense of mounting such an expedition.

Still, sales of propylene on Earth are estimated at $90 billion annually. But private industry probably won’t fly to Titan to suck out its hydrocarbon riches any time soon. Such a scheme would probably run afoul of international treaties, which call for protecting the environment of other worlds. Fossil fuels are also likely to remain relatively cheap, plentiful, and easy enough to access for many years that space-based extraction of them will remain laughable. Source: Wired

A Traveller ‘s Guide to the Planets – Saturn: