Behold: Arp 273 – a great interstellar battle featuring upper galaxy UGC 1810 and its smaller collisional neighbour UGC 1813. War is hell. To wit:
The overall shape of the UGC 1810 — in particular its blue outer ring — is likely a result of wild and violent gravitational interactions. The blue colour of the outer ring at the top is caused by massive stars that are blue hot and have formed only in the past few million years. The inner part of the upper galaxy — itself an older spiral galaxy — appears redder and threaded with cool filamentary dust. A few bright stars appear well in the foreground, unrelated to colliding galaxies, while several far-distant galaxies are visible in the background. Arp 273 lies about 300 million light years away toward the constellation of Andromeda. Quite likely, UGC 1810 will devour its galactic sidekicks over the next billion years and settle into a classic spiral form.