
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 …
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 | Definition, Formation, Types, Properties, & Facts | Britannica
Jan 7, 2026 · The existence of galaxies was not recognized until the early 20th century. Since then, however, galaxies have become one of the focal points of astronomical investigation. The notable …
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? - sciencenewstoday.org
Mar 19, 2025 · Galaxies are the grand islands of the universe, each one a vast metropolis of stars, gas, dust, dark matter, and endless possibility. From tiny dwarfs to sprawling giants, galaxies tell the story …
Galaxy Formation and Evolution - Harvard–Smithsonian Center for ...
Galaxies are home to most of the stars in the universe, and they form the beads of the cosmic jewelry that defines structure on the largest scales. But galaxies haven’t always been around, and they have …
What is a galaxy? - BBC Sky at Night Magazine
Jan 18, 2024 · Galaxies are among the largest and most beautiful objects in the night sky. These huge swirling masses are where almost every star in the Universe is born, lives and dies.
What Is a Galaxy? - Scientific American
May 9, 2025 · Huge clouds of invisible dark matter accumulated regular matter (in the form of gas) via gravity, which eventually collapsed to form galaxies and the stars in them.
Galaxies | Latest Developments in Galaxy Formation and Evolution
Learn about galaxies near and far, from the earliest to form in the distant universe to stunning spirals in our neighborhood.
James Webb Space Telescope discovers young galaxies age rapidly: …
3 days ago · The James Webb Space Telescope, Hubble Space Telescope and Atacama Large Millimeter/submillimeter Array have found young galaxies growing up incredibly fast.