Oct 22, 2024 · 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 smallest can contain a few thousand stars and span just a few hundred light-years.

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.

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).

Apr 16, 2025 · 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 called Earth that is part of our solar system. But where is our solar system? It’s …

2 days ago · 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.

Oct 22, 2024 · Scientists sometimes categorize galaxies based on their shapes and physical features. Other classifications organize galaxies by the activity in their central regions – powered by a supersized black hole – and the angle at which we view them.

Mar 26, 2025 · The galaxy JADES-GS-z13-1, observed just 330 million years after the big bang (corresponding to a redshift of z=13.05), shows bright emission from hydrogen known as Lyman-alpha emission. This is surprising because that emission should have been absorbed by a dense fog of neutral hydrogen that suffused the early universe.

There are probably more than 170 billion galaxies in the observable universe. Astronomers sort galaxies into three main types by their shapes: spirals, ellipticals, and irregulars, and further divide them into subtypes based on their particular characteristics. Find out more about one of the galaxies by selecting it below.

Jun 5, 2024 · A galaxy is a massive, gravitationally bound system that consists of stars, stellar remnants, interstellar gas, dust, dark matter, and other celestial objects. The various components of a galaxy orbit around a common center, often a supermassive black hole.

Jan 19, 2022 · Quasars are actually some of the brightest objects in the universe. There are no quasars near our Milky Way. Explore the different types of galaxies!