Astrochemical Model Digs Into The Universe's Missing Sulfur

The Mystery of Missing Sulfur in the Universe

Sulfur ranks among the most plentiful elements scattered throughout the cosmos. Observations of diffuse interstellar clouds reveal significant sulfur presence—aligning well with predictions based on stellar fusion processes. Yet, a curious anomaly arises when examining dense, cold molecular clouds, the very environments where stars are born. Here, a staggering 99% of the anticipated sulfur appears to be absent.

This conundrum, known as the "missing sulfur problem," has perplexed scientists for decades. A prevailing hypothesis suggests that this elusive sulfur may be trapped within icy dust grains, concealing it from our observations and complicating efforts to fully understand its cosmic distribution.