Galaxies - NASA Science
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 - 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 …
Galaxy | Definition, Formation, Types, Properties, & Facts | Britannica
2024年11月25日 · 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 …
Galaxy Formation and Evolution - Center for Astrophysics
But 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 …
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
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 that …
What’s a galaxy? All you need to know - EarthSky
2024年5月21日 · Galaxies are the building blocks of our universe. Their distribution isn’t random, as one might suppose. Instead, galaxies reside along unimaginably long filaments across the …
Galaxies - HubbleSite
2024年10月28日 · 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, …
Galaxies | Astronomy.com
Galaxies are vast collections of stars, gas, dust, and dark matter bound together by gravity. There are hundreds of billions of galaxies in the universe. The new study suggests that miniture...
Galaxies—facts and information - National Geographic
2019年4月17日 · 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 …
Galaxy | COSMOS - Swinburne
A galaxy is a gravitationally bound entity, typically consisting of dark matter, gas, dust and stars. Galaxies populate the Universe, mainly residing in clusters and groups. There are thought to …