Ok, I know neutron stars are mainly composed of neutrons. But also, they have some protons and normal nuclei at their surfaces. Is this crust of protons needed to keep the neutrons below stable? As in, if it disappeared, would the neutrons below start decaying back to protons to form its 'protective' layer? Or would the neutrons be stable and not decay - the protons are just leftovers from the creation of the neutron star.