  Our high time resolution observations of individual giant pulses in the Crab
pulsar show that both the time and frequency signatures of the interpulse are
distinctly different from those of the main pulse. Giant main pulses can
occasionally be resolved into short-lived, relatively narrow-band nanoshots. We
believe these nanoshots are produced by soliton collapse in strong plasma
turbulence. Giant interpulses are very different. Their dynamic spectrum
contains narrow, microsecond-long emission bands. We have detected these
proportionately spaced bands from 4.5 to 10.5 GHz. The bands cannot easily be
explained by any current theory of pulsar radio emission; we speculate on
possible new models.
