An important building block of life can form long before stars



Comets are the most pristine material in our Solar System and reflect the molecular composition present when our solar system form. The recognition of glycine in the coma of comet 67P/Churyumov-Gerasimenko and samples returned them to Earth from the Stardust mission proposes that amino acids, for example, glycine, form a long time before stars. However, until recently, it was believed that glycine development required energy, setting clear limitations to the environment in which it tends to be formed.

In the new study, an international team of astrophysicists and astrochemical modelers mostly based at the Laboratory for Astrophysics at Leiden Observatory, the Netherlands, suggest that glycine, and very likely other amino acids, form in dense interstellar clouds well before they transform into new stars and planets. Glycine can form on the surface of icy dust grains, in the absence of energy, through ‘dark chemistry.’

Dr. Sergio Ioppolo, from the Queen Mary University of London and lead author of the article, said: “Dark chemistry refers to chemistry without the need of energetic radiation. In the laboratory, we were able to simulate the conditions in dark interstellar clouds where thin layers of ice cover cold dust particles and subsequently processed by impacting atoms causing precursor species to fragment and reactive intermediates to recombine.”