An international team including Southwest Research Institute, Leiden University and NASA used observations from the James Webb Space Telescope (JWST) to achieve the darkest-ever view of a dense interstellar cloud. These observations have revealed the formation of a virtual treasure chest of ice from the early universe, providing new insights into the chemical processes of one of the coldest and darkest places in the universe as well as the origins of the molecules that make up planetary atmospheres.
said SwRI research scientist Dr. Dana Kassem, co-author of the study published in natural astronomy. “The clouds are so dense that these ices were mostly shielded from the harsh radiation of nearby stars, so they are absolutely pure. These are the first ices to form and also contain vital elements, which are important for life.”
NASA’s JWST has a 6.5-meter-wide mirror that provides remarkable spatial resolution and sensitivity, optimized for infrared light. As a result, the telescope was able for the first time to photograph 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 for a better understanding of the molecular origins of protoplanetary disks and atmospheres of planets and other solar system bodies,” said Kasim.
Most interstellar ices contain very small amounts of elements such as oxygen and sulfur. Kasem and her colleagues seek to understand the lack of sulfur in interstellar ice.
“The ice we’ve observed only contains about 1% of the sulfur we expect. 99% of that sulfur is locked up elsewhere, and we need to figure out where to understand how sulfur will eventually be incorporated into planets that might host life.”
In the study, Kasim and colleagues suggested that sulfur may be trapped in reactive minerals such as iron sulfide, which may react with ice to form the observed sulfur-bearing ice.
“Iron sulfide is a highly reactive mineral that has been detected in the accretion disks of young stars and in samples returned from comets. It is also the most common sulfide mineral in lunar rocks,” Qasim said. “If sulfur is trapped in these minerals, that could explain the decreased amount of sulfur in interstellar ice, affecting where sulfur is stored in our solar system. For example, the atmosphere of Venus contains molecules containing sulfur, in which it could come in. Sulfur is partly from interstellar minerals.