The raw images of the medium resolution imager on the Deep Impact spacecraft from June 22 - June 24, 2005 are displayed in this movie.
A brightening by a factor of about 5 and rapid decay to baseline brightness can be seen on June 22. As the comet moves through space, background stars pass into and out of the field of view, and cosmic rays hitting the detector give an appearance of flickering, that is an artifact of space cameras that remain to be removed.