An international team from the Southwest Research Institute, Leiden University and NASA used observations from the James Webb Space Telescope (JWST) to get the darkest ever view of the dense interstellar cloud. This led to the discovery of the composition of a virtual ice treasure chest from the early universe, providing new insights into the chemical processes in one of the coldest and darkest places in the universe and the origins of the molecules that make up planetary atmospheres.

SwRI scientist Dr. “JWST has allowed us to study ice on dust particles in the darkest regions of interstellar molecular clouds,” said Danna Kasim. Nature Astronomy. “The clouds are so dense that these ices are largely shielded from the harsh radiation of nearby stars, so they are fairly pristine. These are the first to form, including biogenic elements important to life.”

NASA’s JWST has a 6.5 meter wide mirror optimized for infrared light, providing excellent spatial resolution and sensitivity. As a result, the telescope was able for the first time to obtain images of the densest and darkest clouds in the universe.

“These observations provide new insights into chemical processes in one of the coldest and darkest places in the universe to better understand the molecular origins of preplanetary disks, planetary atmospheres, and other objects in the Solar System,” said Qasim.

Most interstellar ice contains very small amounts of elements such as oxygen and sulfur. Kasim and his co-authors are trying to understand the absence of sulfur in interstellar ice.

“The ice we observe contains only 1% of the sulfur we expect. 99% of that sulfur is locked elsewhere, and we need to understand how sulfur ends up on planets that could eventually host life.”

In the study, Qasim and colleagues suggest that sulfur may be retained in reactive minerals such as iron sulfide, which can react with ice to form the observed sulfur-containing ice.

“Iron sulfide is a highly active mineral found in accretion disks of young stars and in samples from comets. Qasim is also the most abundant sulfide mineral in Moon rocks,” he said. “If sulfur is locked in these minerals, it could explain the low sulfur abundance in interstellar ices, which in turn could explain the lower sulfur abundance of sulfur in solar rocks.” it has implications for where it is stored in our system. For example, there are sulfur-containing molecules in the atmosphere of Venus, where the sulfur may have originated in part from inherited interstellar minerals.”