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 …

Nov 27, 2025 · The existence of galaxies was not recognized until the early 20th century. Since then, however, galaxies have become one of the focal points of astronomical investigation. …

Mar 19, 2025 · Galaxies are the grand islands of the universe, each one a vast metropolis of stars, gas, dust, dark matter, and endless possibility. From tiny dwarfs to sprawling giants, …

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...

Mar 23, 2025 · Typically, galaxies are millions of light-years apart. Galaxies are the building blocks of our universe. Their distribution isn’t random, as one might suppose. Instead, galaxies …

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.

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.

In this chapter, we start our exploration of the vast realm of galaxies. Like tourists from a small town making their first visit to the great cities of the world, we will be awed by the beauty and …

Oct 22, 2024 · Our Milky Way is one example of a broad class of galaxies defined by the presence of spiral arms. These galaxies resemble giant rotating pinwheels with a pancake-like …