- 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 the Milky Way galaxy that contains the Solar System
- Galaxy | Definition, Formation, Types, Properties, Facts | Britannica
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 Virtually all galaxies appear to have been formed soon after the universe began, and they pervade all space that is viewable by modern telescopes
- galaxy（英文单词）_百度百科
galaxy，英语单词，主要用作名词，主要意思为“星系；银河，银河系”等。
- Galaxies - NASA Science
Most galaxies are between 10 billion and 13 6 billion years old Some are almost as old as the universe itself, which formed around 13 8 billion years ago Astronomers think the youngest known galaxy formed approximately 500 million years ago Galaxies can organize into groups of about 100 or fewer members held together by their mutual gravity
- What Is a Galaxy? | NASA Space Place – NASA Science for Kids
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?
- Galaxies—facts and information | National Geographic
In our own galaxy, the Milky Way, the sun is just one of about 100 to 400 billion stars that spin around Sagittarius A*, a supermassive black hole that contains as much mass as four million suns
- What’s a galaxy? All you need to know - EarthSky
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
- Galaxy Formation and Evolution - Center for Astrophysics
The galaxy M101 as seen by NASA's Hubble Space Telescope reveals its beautiful and complex spiral arms Though spiral galaxies are the most common type of large galaxy, many details of how they form and evolve are still mysterious
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