Evolution

Definition

Evolution in astronomy refers to the process by which galaxies form, change, and develop over time. It encompasses the physical processes that drive these transformations across billions of years.

5 Must Know Facts For Your Next Test

1. Galactic evolution is influenced by interactions such as mergers and collisions with other galaxies.
2. The morphology of a galaxy can change over time due to internal processes like star formation and external influences like gravitational interactions.
3. Observations of distant galaxies allow astronomers to look back in time and understand the early stages of galactic evolution.
4. Dark matter plays a crucial role in the formation and evolution of galaxies by providing the necessary mass for gravitational collapse.
5. Galaxies evolve from irregular shapes to more structured forms such as spiral and elliptical galaxies.

Review Questions

• How do interactions with other galaxies influence galactic evolution?
• Why are observations of distant galaxies important for understanding galactic evolution?
• What roles do dark matter and star formation play in the evolution of galaxies?

Related terms

Redshift:

The displacement of spectral lines toward longer wavelengths observed in distant celestial objects, indicating they are moving away from us.

Hubble's Law:

A law stating that the recessional velocity of a galaxy increases with its distance from Earth, implying an expanding universe.

Dark Matter:

A form of matter that does not emit light or energy but exerts gravitational force, significantly affecting the structure and evolution of galaxies.