The QCD Phase Diagram and Explosive Astrophysics

I give a brief overview of our current understanding of the QCD phase diagram at finite temperature and baryon density. I emphasize phase transitions which occur at high density and low temperature (relative to the QCD scale), such as transition(s) to the color superconducting and chirally symmetric phases. These transitions might occur during violent astrophysical activity such as type II supernovae core bounce or neutron star mergers, and I discuss the possible consequences.