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 …

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-years across. The …

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. The notable …

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 tell the story …

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...

Nov 7, 2025 · Explore the main types of galaxies: spiral, elliptical, barred and irregular with stunning astrophotography and insights into how galaxies form, collide & evolve.

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 variety of the …

Named galaxies This is a list of galaxies that are well known by something other than an entry in a catalog or list, or a set of coordinates, or a systematic designation.

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 shapes …