Collisions

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

1. Galactic collisions can lead to the formation of new star systems as gas clouds compress and trigger star formation.
2. Our Milky Way galaxy is predicted to collide with the Andromeda galaxy in about 4.5 billion years.
3. Collisions between smaller galaxies can result in the creation of larger, more complex structures such as elliptical galaxies.
4. Evidence of past collisions in the Milky Way includes streams of stars and disrupted stellar orbits.
5. Galactic collisions do not typically result in direct stellar collisions due to the vast distances between individual stars.

Review Questions

• How do galactic collisions contribute to star formation?
• What is expected to happen when the Milky Way collides with the Andromeda galaxy?
• Why are direct stellar collisions rare during galactic mergers?

Related terms

Galaxy:

A massive system composed of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity

Star Formation:

The process by which dense regions within molecular clouds in interstellar space collapse to form stars

Elliptical Galaxy:

A type of galaxy with an ellipsoidal shape and a smooth, nearly featureless brightness profile