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 …

May 2, 2025 · 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 …

Oct 21, 2025 · 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 …

May 9, 2025 · Huge clouds of invisible dark matter accumulated regular matter (in the form of gas) via gravity, which eventually collapsed to form galaxies and the stars in them.

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 to also contain...

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 …

This page explains that galaxies are vast systems made up of stars, remnants, interstellar medium, and dark matter, named after the Greek word for milk. There are approximately 170 …

Learn about galaxies near and far, from the earliest to form in the distant universe to stunning spirals in our neighborhood.

This is a list of galaxies that are visible to the naked eye, for at the very least, keen-eyed observers in a very dark-sky environment that is high in altitude, during clear and stable weather.

Oct 22, 2024 · Types of Galaxies Scientists sometimes categorize galaxies based on their shapes and physical features. Other classifications organize galaxies by the activity in their central …