In interstellar space, a complex organic compound containing a sulfur atom has been detected for the first time: the molecule thiin (C6H6S). The substance had previously been known only from laboratory experiments and meteorite samples. Its unique spectral “signature” was recorded in the G+0.693–0.027 cloud, located near the center of the Milky Way, 27,000 light-years from Earth.
To confirm the discovery, scientists carried out a laboratory synthesis of thiin from thiophenol and used a specially built spectrometer. Radio signals matching the laboratory data were found in observations from the IRAM and Yebes telescopes. This made it possible to confirm the presence of the molecule in the star-forming region with high precision.
Sulfur is one of the key elements in living organisms on Earth: it is found in amino acids, proteins, and enzymes. Previously, only simple sulfur-containing molecules had been found in interstellar space. Thiin is not only larger, but also structurally similar to substances found in meteorites. The discovery makes the existence of life elsewhere in the galaxy statistically more likely, since key chemical components for biology are already present in interstellar medium before planet formation.
