The ultimate collision: Neutron stars rattle, shine and sparkle
GW170817, the first observed neutron star merger, marks the beginning of a new era of multi-messenger astronomy. The gravitational and electromagnetic waves observed from this event confirmed theoretical expectations and provided new insights about the properties of neutron stars and the synthesis of heavy elements in the universe. I will describe the underlying nuclear physics relevant to modeling these extreme collisions and discuss how future observations and improved models can help address long-standing questions in nuclear and particle astrophysics. During the next decade multi-messenger observations of several neutron star mergers, detailed x-ray observations of neutron stars in our galaxy, and the detection of neutrinos from a much anticipated galactic supernova can revolutionize astrophysics if we can develop and validate multi-physics models to interpret this data. I will discuss some of the open questions in this context and efforts to address them.