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.
Galaxy | Definition, Formation, Types, Properties, & Facts | Britannica
WEBSep 29, 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.
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 …
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
WEBSep 27, 2024 · 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 that is part of our solar system. But where is our solar system? It’s a small part of the Milky Way Galaxy.
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.
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...
Galaxy Formation and Evolution - Center for Astrophysics
WEBBut galaxies haven’t always been around, and they have changed over the universe’s 13.8 billion-year history. Astronomers study the ways galaxies form and evolve by comparing the different shapes across the history of the cosmos, …
What’s a galaxy? All you need to know - EarthSky
WEBMay 21, 2024 · What is a galaxy? A galaxy is a vast island of gas, dust and stars in an ocean of space. Typically, galaxies are millions of light-years apart. Galaxies are the building blocks of our universe....
The Milky Way Galaxy - Harvard–Smithsonian Center for …
WEBToday, astronomers study the Milky Way to understand its history, structure, contents, and our place in the galaxy. Like most other large galaxies, the Milky Way harbors a supermassive black hole at its center. Known as Sagittarius A* — abbreviated as Sgr A* — this galaxy is about four million times the mass of the Sun.
What is a Galaxy? - YouTube
WEBGalaxies are concentrations of stars, gas, dust, and dark matter. They come in a variety of shapes and sizes. Some are fated to collide, like the Milky Way and Andromeda. Credit: NASA and J ...