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.
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
2025年1月2日 · 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?
List of galaxies - Wikipedia
There are an estimated 100 billion galaxies in all of the observable universe. [1] . On the order of 100,000 galaxies make up the Local Supercluster, and about 51 galaxies are in the Local Group (see list of nearest galaxies for a complete list).
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, and histories of galaxies — whether alone, as part of small groups, or within immense clusters.
NASA’s Hubble Traces Hidden History of Andromeda Galaxy
2025年1月16日 · In the years following the launch of NASA’s Hubble Space Telescope, astronomers have tallied over 1 trillion galaxies in the universe.But only one galaxy stands out as the most important nearby stellar island to our Milky Way — the magnificent Andromeda galaxy (Messier 31).It can be seen with the naked eye on a very clear autumn night as a faint cigar …
Hubble Space Telescope reveals richest view of Andromeda galaxy …
3 天之前 · This is the largest photomosaic ever made by the Hubble Space Telescope. The target is the vast Andromeda galaxy that is only 2.5 million light-years from Earth, making it the nearest galaxy to ...
Galaxy | Definition, Formation, Types, Properties, & Facts | Britannica
2025年1月11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 stars.
What’s a galaxy? All you need to know - EarthSky
2024年5月21日 · 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...
New 3D Visualization Highlights 5,000 Galaxies Revealed by Webb
2023年7月10日 · This video, a scientific visualization of the galaxies captured as a part of the CEERS (Cosmic Evolution Early Release Science) Survey, showcases a large undertaking by NASA’s James Webb Space Telescope.
Galaxies, the cosmic cities of the universe, explained by ... - Space.com
2021年4月22日 · Galaxies are glittering cities, massive metropolises full of stars, dust, gas, black holes, magnetic fields, cosmic rays, dark matter and more. Separated by millions of light-years of essentially...