An international team with Swiss participation has detected the coldest ice ever measured in a molecular cloud using the James Webb Space Telescope. And, in this frozen environment, fundamental ingredients of life have been identified.
Molecular clouds are interstellar nebulae where the creation of stars occurs. The scientists, including Maria Drozdovskaya, from the University of Bern and the National Research Competence Center(NCCR), measured a temperature of -263 degrees – ten degrees above absolute zero – at the center of the “Chameleon I” molecular cloud, located more than 500 light years from Earth. There are currently forming dozens of young stars: they are close to the center of the cloud, in a particularly cold, dense and difficult to study environment.
These pre-stellar frozen molecules are considered central to the appearance of life on Earth, notes the Bernese alma mater in a press release. Scientists have found water, carbon monoxide and dioxide, ammonia and methane, but also more complex compounds such as methanol.
These measurements are the most precise to date of this dust frozen at very low temperatures. They were carried out using infrared spectrographs from the James Webb telescope, capable of detecting the chemical fingerprint of each molecule.
The scientists were also surprised to find that certain elements such as carbon, hydrogen, oxygen, nitrogen and sulfur were present in lower quantities than expected. These elements are fundamental ingredients for the formation of amino acids in the prebiotic soup.
This tends to indicate, according to the research team, that these elements do not only come from molecular clouds: “It may mean that they are locked in particles of rocky dust”,astronomer Melissa McClure of Leiden Observatory, lead author of the study.
Still, the presence of prebiotic molecules during star formation could be more common than thought, and not just a feature of our solar system, according topublished in the journal Nature Astronomy (read box).
Stéphanie Jaquet and the ats