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 smallest can contain a few thousand stars and span just a few hundred light-years
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), meaning 'milky', a reference to the Milky Way galaxy that contains the Solar System
Galaxy | Definition, Formation, Types, Properties, Facts | Britannica A galaxy is 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 Galaxies usually exist in clusters, some of which measure hundreds of millions of light-years across
What is a Galaxy? - sciencenewstoday. org A galaxy is one of the largest structures in the universe It is a gravitationally bound system made up of stars, planets, gas, dust, dark matter, and often mysterious phenomena such as black holes and energetic cosmic radiation
What is a galaxy? - Live Science Galaxies are groups of stars and other space objects held together by gravity There are more than 100 billion galaxies in the universe, each presenting beautiful structures that can be seen in
What is a galaxy? - BBC Sky at Night Magazine A galaxy is a concentration of millions or billions of stars, gas clouds and pockets of dust, all bound by gravity and swathed in a cocoon of mysterious dark matter
Galaxies Coverage | Space Galaxies Latest about Galaxies Our Milky Way's 'Zone of Avoidance' holds a galaxy supercluster with 30,000 trillion times the sun's mass published May 4, 2026
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