Today is Hubble Space Telescope’s 18th launch anniversary. In celebration, NASA has released 59 views of colliding galaxies constitute the largest collection of Hubble images ever released to the public. Astronomers observe only one out of a million galaxies in the nearby universe in the act of colliding.

However, galaxy mergers were much more common long ago when they were closer together, because the expanding universe was smaller. Astronomers study how gravity choreographs their motions in the game of celestial bumper cars and try to observe them in action.

For all their violence, galactic smash-ups take place at a glacial rate by human standards — timescales on the order of several hundred million years. The images in the Hubble atlas capture snapshots of the various merging galaxies at various stages in their collision.

You can see more images at the Official NASA Hubble Page Here