Science News: The origin of neutron-rich heavy elements in the universe remains a mystery. One possible source could be neutron stars, whose high-pressure, high-gravity interiors could stabilize atoms that could not form otherwise. Collisions between neutron stars would then disperse the atoms into space. Because neutron stars are too far away to study, scientists are trying to determine their composition via computer simulations using the properties of exotic isotopes created in particle accelerators. One such isotope, thought to exist in the crust of neutron stars, is zinc-82. Using a facility at CERN, Robert Wolf of the University of Greifswald in Germany and colleagues were able to isolate a pure sample of zinc-82 and determine its mass. By comparing the mass with predictions from computer modeling, the researchers were able to rule out zinc-82 as a constituent of neutron stars. Despite the negative result, the technique shows potential for “pin[ning] down the characteristics of other exotic nuclei that may exist in neutron stars,” writes Andrew Grant for Science News.