Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Collisions are interactions where two or more astronomical bodies exert forces on each other, altering their trajectories and sometimes merging. They play a crucial role in the formation and evolution of galaxies.
5 Must Know Facts For Your Next Test
Galactic collisions can lead to the formation of new star systems as gas clouds compress and trigger star formation.
Our Milky Way galaxy is predicted to collide with the Andromeda galaxy in about 4.5 billion years.
Collisions between smaller galaxies can result in the creation of larger, more complex structures such as elliptical galaxies.
Evidence of past collisions in the Milky Way includes streams of stars and disrupted stellar orbits.
Galactic collisions do not typically result in direct stellar collisions due to the vast distances between individual stars.