Michael Duncan and colleagues from the University of Georgia made this shocking discovery: interstellar clouds are basically a giant mothball!
... researchers from the University of Georgia have just shown for the first time that one component of clouds emitting unusual infrared light know as the Unidentified Infrared Bands (UIRs) is a gaseous version of naphthalene, the chief component of mothballs back on Earth. The UIRs have been seen by astronomers for more than 30 years, but no one has ever identified what specific molecules cause these patterns.
But what does it mean ... what is the napthalene for? Well, isn't it obvious? To ward off the Arachnids, of course!
It also explains why SET hasn't been able to find anything so far.