Researchers, including Paola Caselli, Barbara Michela Giuliano, and Basile Husquinet from MPE, have used the James Webb Space Telescope (JWST) to investigate dense cloud cores in the Chamaeleon I region and have discovered weak spectroscopic features known as 'dangling OH'. These features indicate that water molecules in the ice are not fully bound, shedding light on the structure of interstellar water ice. The sensitivity of the JWST allows for the measurement of weaker features, providing new clues about the modifications of icy grains. The detection of 'dangling OH' features can be used to study the porosity, physical structure, and chemical composition of interstellar ices. This finding suggests the presence of potentially 'fluffy' icy grains in the cloud, which can impact chemistry and the degree of chemical complexity. The discovery also has implications for studying planet formation and the evolution of ices from molecular clouds to protoplanetary disks to planets. [a772c2ca]