
Galaxy - Wikipedia
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. [1][2] The word is derived from the Greek galaxias (γαλαξίας), literally …
Galaxy | Definition, Formation, Types, Properties, & Facts | Britannica
Nov 27, 2025 · A galaxy is any of the systems of stars and interstellar matter that make up the universe. Many such assemblages are so enormous that they contain hundreds of billions of …
Galaxies - NASA Science
May 2, 2025 · Galaxies consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity. The largest contain trillions of stars and can be more than a million light …
What is a Galaxy? - sciencenewstoday.org
Mar 19, 2025 · The Basics: What Is a Galaxy, Really? At its core, a galaxy is a massive, gravitationally bound system consisting of stars, stellar remnants, interstellar gas, dust, and …
What’s a galaxy? All you need to know - EarthSky
Mar 23, 2025 · A galaxy can contain hundreds of billions of stars and be many thousands of light-years across. Our own galaxy, the Milky Way, is around 100,000 light-years in diameter.
Galaxies—facts and information | National Geographic
Galaxies are sprawling systems of dust, gas, dark matter, and anywhere from a million to a trillion stars that are held together by gravity. Nearly all large galaxies are thought to also contain...
What is a galaxy? - BBC Sky at Night Magazine
Jan 18, 2024 · A galaxy is a concentration of millions or billions of stars, gas clouds and pockets of dust, all bound by gravity and swathed in a cocoon of mysterious dark matter.
Types of Galaxies | Pictures, Facts, and Information
Nov 7, 2025 · Although these are the four main types, there are various types of galaxies, and they are classified by shape. A galaxy is a cluster of stars, gas, and dust that is kept together …
List of galaxies - Wikipedia
The first attempts at systematic catalogues of galaxies were made in the 1960s, with the Catalogue of Galaxies and Clusters of Galaxies listing 29,418 galaxies and galaxy clusters, …
Galaxy Types - NASA Science
5 days ago · Our Milky Way is one example of a broad class of galaxies defined by the presence of spiral arms. These galaxies resemble giant rotating pinwheels with a pancake-like disk of …