  We present spectroscopic and high-precision photometric observations,
spanning the optical UV to the far red, before, during, and after the NASA Deep
Impact event of July 4, 2005. The inner 2000 km of the pre and post-impact coma
was about 0.3 magnitude redder in B-R than in the outer coma. The pre-impact
spectrum was a faint reflected solar spectrum dominated by molecular emissions
extending > 40000 km from the nucleus. The post-impact light curve in R and I
showed a rapid rise consistent with an expanding optically thick cloud during
the first 18 minutes after impact. During the next 8 minutes the cloud became
optically thin. Sixty minutes after impact the impact R-band flux reached a
plateau at 7.5 x 10-15 erg cm-2 s-1 {\AA}-1, the comet brightening by a factor
of ~4.3 above its pre-impact value observed in a 15" aperture. The mean
expansion velocity of the grains during the first 49 minutes was 229 {\pm} 49 m
s-1. The spectrum became dominated by scattered sunlight during the first hour
after impact. The volume scattering function (VSF) observed 32 minutes after
impact shows strong reddening. At 49 minutes, however, the VSF shows an
additional two-fold increase in the blue but only a 20 per-cent increase at
5500{\AA}. Post-impact spectra and R-I photometry showed rapid reddening. The
particle size distribution, dominated by 1 to 2.5 micron particles shortly
after impact, changed dramatically during the first hour due to sublimation of
water-ice particles of this size. On the night following impact the comet was
still substantially brighter than before impact, but R-I had returned to its
pre-impact value. B-R remained significantly redder. The ejecta 25 hours after
impact was fan-shaped subtending ~180{\deg} roughly symmetrical about position
angle 225{\deg}. The mean expansion velocity 90{\deg} from the direction to the
Sun was 185{\deg} 12 m s-1.
