
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 'milky', a reference to …
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 stars. Galaxies …
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-years across. The …
Galaxy - ESA/Hubble
Galaxies are collections of stars, dust, gas, and dark matter, which are bound together by the gravitational attraction that results from their own mass. A small dwarf galaxy contains a few million …
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’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.
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 dark matter.
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.
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
Sep 25, 2025 · What Is a Galaxy? The Short Answer: A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth …
What Is a Galaxy? - Scientific American
May 9, 2025 · Very generally speaking, galaxies are tens of thousands to hundreds of thousands of light-years across and have millions to several trillions of stars. Our Milky Way, for example, is about...