  Understanding the explosion mechanism of core collapse supernovae is a
problem that has plagued nuclear astrophysicists since the first computational
models of this phenomenon were carried out in the 1960s. Our current theories
of this violent phenomenon center around multi-dimensional effects involving
radiation-hydrodynamic flows of hot, dense matter and neutrinos. Modeling these
multi-dimensional radiative flows presents a computational challenge that will
continue to stress high-performance computing beyond the teraflop to the
petaflop level. In this paper we describe a few of the scientific discoveries
that we have made via terascale computational simulations of supernovae under
the auspices of the SciDAC-funded Terascale Supernova Initiative.
