Neutron-skin as a portal to neutron star properties: With the new era opened up by the LIGO and VIRGO observation of neutron-star mergers, multi-messenger astronomy will provide us with new ways to constrain the equation of states of neutron-rich matter. Stronger constraints will be obtained by combining such future data with observations on finite nuclei. Indeed, neutron-rich nuclei provide a portal to study neutron-rich matter, in that they form a neutron-skin around their surface which is directly related to the equation of state of nuclear matter. As reported in Nature (2016), TRIUMF theorists and international collaborators provided the first ab initio computation of calcium-48 (48Ca), a nucleus with 20 protons and 28 neutrons. It was predicted that a neutron-skin is formed, though much smaller than previously thought, calling for new experimental investigations.