The Atlas of Peculiar Galaxies is a catalog of 338 peculiar galaxies produced by Halton Arp in 1966. Although most are tiny and hard to image clearly, they are some of the most interesting looking galaxies in the universe. Many of these objects seem to look like galaxy mergers, but Dr. Arp did not agree with that idea and believed that such objects were examples of "ejections". He even writes in his controversial book Seeing Red (1998) that "for me, the whole lesson of the Atlas of Peculiar Galaxies was that galaxies are generally ejected material." Arp was a controversial figure - he also was a vocal critic of the Big Bang theory (through which he lost his access to the Palomar Observatory) and advocated a different interpretation of cosmic redshift.
Despite the controversy, they is no doubt that the galaxies of Arp's collection are magnificent. Beyond the merger vs. ejection question, the structures raise interesting questions about how they were formed and where they are headed. We are seeing just a snapshot in time of a process whose time and distance scale is unimaginable for us.

The images below are listed in order of Arp number. For each image, I have included a mouseover comparison of my image to the original Arp image, taken about 60 years ago with the largest telescope in the world at the time.

My YouTube presentation of how I captured this catalog is here - https://www.youtube.com/watch?v=aEbw05FAMfk