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 …

6 天之前 · 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 …

2025年5月2日 · 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 …

2025年5月9日 · In modern times, though, we use “galaxy” more generically to refer to any large system of stars, gas, dust and dark matter, all held together by their mutual gravity.

2025年3月23日 · A galaxy can contain hundreds of billions of stars and be many thousands of light-years across. Our own galaxy, the Milky Way, is around 100,000 light-years in diameter.

Galaxies are home to most of the stars in the universe, and they form the beads of the cosmic jewelry that defines structure on the largest scales. But galaxies haven’t always been around, …

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 …

2015年9月9日 · 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 …

Everything in a galaxy moves around a centre of mass, which is also an effect of gravity. There are various types of galaxies: elliptical, spiral and lenticular galaxies, which can all be with or …

6 天之前 · Learn about the three general types of galaxies: spiral, elliptical, and irregular. Almost all current systems of galaxy classification are outgrowths of the initial scheme proposed by …