Dictionary of Space Concepts

Image/Video/Audio Source:

Short Definition:
A galaxy is a system composed of a star and an interstellar matter that is held together by the gravity force.

Detailed Definition:
A galaxy is a vast collection of stars, their solar systems, gas, and dust. In the centre of the galaxy a massive black hole is placed. Galaxies have different shapes from one another, with variations deriving from how the systems were created and later evolved. A few galaxies resemble our own in spiral shape. They possess curved arms that give it a pinwheel-like appearance. Others have smooth surfaces and oval forms. Scientists refer to them as elliptical galaxies. There are galaxies that are neither spirals nor ovals, either. They mimic blobs and have amorphous forms. Each of these galaxies emits light that we can see from its stars. In the future some galaxies will collide like NGC 4567 and NGC 4568 (commonly referred to as the Butterfly galaxies) started to do so and some will drift apart that the light from its stars will not reach the Earth.

Etymology:
Old French from medieval Latin galaxia, from Greek galaxias (kuklos) ‘milky (vault)’, from gala, galakt-‘milk’.

Sample Sentence(s):
When the sky is dark, centre of our galaxy is perfectly visible.

Translations:
French:
Une galaxie

German:
die Galaxie

Polish:
Galaktyka

Swedish:
En galax

Spanish:
Una galaxia

Links to Videos/Articles:
https://spaceplace.nasa.gov/galaxy/en/
https://en.wikipedia.org/wiki/Galaxy
https://www.britannica.com/science/galaxy
https://edition.cnn.com/2022/08/10/world/colliding-galaxies-gemini-north-image-scn/index.html