Two years ago this week Caltech astronomers were using the 200-inch Hale Telescope to observe the fractured Comet 73P/Schwassmann-Wachmann 3 as it came relatively close to Earth.
The comet was discovered by Arnold Schwassmann and Arno Arthur Wachmann in 1930. In 1995 the comet was found to have broken up into four fragments in 1995. By its 2006 passage it had further split into dozens, if not hundreds, of pieces.
The animated gif above shows a sequence of 15 looped images showing the in the foreground against distant stars and galaxies which appear to streak across the frame. Because the comet was moving at a different rate across the sky than the stellar background, the telescope was tracking the comet's motion and not that of the stars. Many fragments of the comet are visible as nearly stationary objects in the movie. In all, 16 new fragments were discovered as a part of the Palomar observations.