  Nuclear pasta, with nucleons arranged into tubes, sheets, or other complex
shapes, is expected in core collapse supernovae (SNe) at just below nuclear
density. We calculate the additional opacity from neutrino-pasta coherent
scattering using molecular dynamics simulations. We approximately include this
opacity in simulations of SNe. We find that pasta slows neutrino diffusion and
greatly increases the neutrino signal at late times of 10 or more seconds after
stellar core collapse. This signal, for a galactic SN, should be clearly
visible in large detectors such as Super-Kamiokande.
