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 …

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 …

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 …

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.

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.

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...

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.

Nov 8, 2023 · A galaxy is a large system of stars, gas (mostly hydrogen), dust and dark matter that orbits a common center and is bound together by gravity — you can think of them as "island universes."

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 …

2 days ago · Stunning new images from NASA's Chandra X-ray Observatory reveal galaxy clusters in vivid colors, showing how supermassive black holes heat and shape surrounding gas using a novel …