Astrochemical model digs into the universe's missing sulfur

Article excerpt

Sulfur is one of the most abundant elements in the universe. If you peer into a diffuse interstellar cloud, you find loads of it, about the amount expected based on fusion patterns in the stars it was born in. However, if you look at a dense, cold molecular cloud, the kind where those stars actually form, it seems like 99% of the sulfur expected to be there is missing. Scientists have puzzled over this "missing sulfur problem" for decades, though a leading theory is that the element hides in icy dust grains, making it hard to detect.