Sitting 10.5 million light-years from Earth, the two intertwining islands of stars are known as the antennae galaxies due to the two, spindly arms coming out from the galactic core that look similar to insect antenna.
These antenna-like structures—made of millions of stars—were originally spiral arms, a normal part of a galaxy. Over time they became gravitationally distorted and drawn out into space during the initial collision between the galaxies 300 million years ago.
Astronomers believe that billions of years in the future, our own Milky Way will suffer the same fate, smashing into our neighboring Andromeda galaxy and eventually merging into one. (Related: "Earth Likely to Relocate in Galactic Collision.")