Galaxy - Wikipedia
WebA 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 the Milky Way galaxy that contains the Solar System.
Galaxies - NASA Science
WebGalaxies 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 smallest can contain a few thousand stars and span just a …
Galaxies—facts and information - National Geographic
WebApr 17, 2019 · 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...
Galaxies | HubbleSite
WebJan 31, 2024 · Galaxies are vast cosmic islands of stars, gas, dust, and dark matter held together by gravity. Hubble’s keen eye has revealed intricate details of the shapes, structures, and histories of galaxies — whether alone, as part of small groups, or within immense clusters.
Galaxy | Definition, Formation, Types, Properties, & Facts
WebApr 22, 2024 · galaxy, 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. Nature has provided an immensely varied array of galaxies, ranging from faint, diffuse dwarf objects to brilliant spiral-shaped giants.
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
Web5 days ago · A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. When you look up at stars in the night sky, you’re seeing other stars in the Milky Way.
Galaxies Over Time - NASA JWST
WebThe James Webb Space Telescope is observing galaxies far back in time and hopefully answer these questions. By studying some of the earliest galaxies and comparing them to today's galaxies we may be able to understand their growth and evolution.
Hubble's Galaxies - NASA Science
WebApr 30, 2024 · Overview. Spiral Galaxies. Elliptical Galaxies. Irregular Galaxies. Hubble's Impact. Galaxies are the visible foundation of the universe; each one a collection of stars, planets, gas, dust, and dark matter held together by gravity. Hubble’s observations give us insight into how galaxies form, grow, and evolve through time.
Size, composition, and structure of galaxies | Britannica
Webgalaxy, Any of the billions of systems of star s and interstellar matter that make up the universe. Galaxies vary considerably in size, composition, structure, and activity, but nearly all are arranged in groups, or clusters, containing from a few galaxies to as many as 10,000.
What Is a Galaxy? (article) | Galaxies | Khan Academy
WebGalaxies are titanic swarms of tens of millions to trillions of stars, orbiting around their common center of gravity. They also contain interstellar gas and dust. Galaxies show a range of shapes that astronomers group into three basic classes: spiral, elliptical, and …
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