34 Cosmic Galaxy Facts

By James Israelsen, Associate Writer

Published January 4, 2022

A galaxy is a group of celestial bodies caught within a massive gravitational field._[3]
Many of the galaxies in the universe were formed through collisions of raw matter with other already existing galaxies._[3]
The Antennae galaxies are two spiral galaxies that have collided with each other in a region 70 million light-years away from Earth._[3]
Our sun is located in the Orion Arm of the Milky Way galaxy._[3]
Planets are formed by pieces of rock and ice that travel through a galaxy until they get caught in a sun's gravitational pull._[3]
Scientists estimate that there are billions of solar systems in the Milky Way galaxy alone._[3]
The command "Okay Google" was chosen in homage to a famous line in the bestselling novel The Hitchhiker's Guide to the Galaxy._[1]
The Milky Way galaxy was initially formed by stars clustering together in discs of primordial gases; these grew in size as our galaxy collided with neighboring galaxies, attracting some of their materials._[3]
A "starburst" galaxy is a galaxy with an unusually high amount of gas and dust, resulting in a high rate of star production._[3]

The starburst galaxy Messier 82 is shown here, captured by the Hubble telescope (ESA/Hubble)

The Milky Way galaxy is currently growing in size, thanks to its strong gravitational pull, which attracts matter from two neighboring galaxies._[3]
The Milky Way has a "galactic halo" on its perimeter, formed of clouds of gases containing clusters of stars._[3]
There are five basic types of galaxies: irregular, elliptical, spiral, barred spiral, and lenticular._[3]
Elliptical galaxies tend to have very little interstellar material in them._[3]
Irregular galaxies appear chaotic, with no definable nucleus or structure._[3]

Kant is renowned for his philosophical treatises but also made scientific contributions

The 19th-century philosopher Immanuel Kant was one of the first people to suggest that there might be collections of stars forming what are now called galaxies, aside from our own Milky Way._[2]
The scientific system for classifying galaxies was created by American astronomer Edwin Hubble._[3]
Barnard's galaxy is only 1.6 million light-years away from Earth, but is very difficult to study because it is too close to the plane in which our own galaxy lies._[3]
Elliptical galaxies are created when two large galaxies collide, and spiral galaxies are formed by two small galaxies fusing together._[3]
Scientists predict that in approximately seven billion years, the Andromeda and Milky Way galaxies will fuse to form one super galaxy that will be the largest galaxy by far in this part of the universe._[3]
A galactic cluster is a structure formed by several galaxies being gravitationally linked._[3]
Most galaxies have a cluster of stars at their core, although the very largest galaxies have a black hole at their center instead._[3]
A blazar is a condensed, active galaxy with a supermassive black hole at its center._[3]

These arms are inconceivably large (ESA/Hubble)

Spiral galaxies have "galactic arms," structures made up of stars, dust, and gas that extend from their centers._[3]
The study of galaxies has revealed the possible existence of "dark matter," which is a hypothetical form of matter that does not absorb or reflect light. It is believed that galaxies could not hold together without such invisible matter._[6]
A "galactic bulge" occurs when a lot of stars end up gathered together in a very compact space at the center of a galaxy._[3]
An "active" galaxy is one that has a supermassive black hole at its center, giving it an abnormally high luminosity._[3]
Galaxies vary greatly in the amount of activity that is occurring in them; while many galaxies have regular star formations happening in them, others have ceased to have stars form at all._[2]
A radio galaxy is a galaxy whose luminosity is made up of light from the radio spectrum of wavelengths._[3]
A quasar is a galaxy that has a black hole at its center and a disc of gas or other particles that are drawn in by the black hole's gravity._[3]
The Andromeda galaxy is the biggest and brightest of the galaxies in Earth's region of the universe._[3]

It's a sight to behold (David (Deddy) Dayag)

The Coma cluster is a grouping of thousands of galaxies, all within the same region of the universe, 330 million light-years away from Earth._[4]
The Magellanic Clouds are two dwarf galaxies that are close neighbors to the Milky Way galaxy. Study of these galaxies is helping astronomers understand how galaxies form._[3]
The Virgo cluster is the largest cluster of galaxies neighboring the Milky Way and is located in the region of the Virgo star constellation._[5]
The 17th-century astronomer Charles Messier was the first to note the existence of other galaxies. He saw "fuzzy objects" in the night sky through his telescope, but he did not know what they were. It wasn't until the early 20th century that scientists hit upon the notion of a galaxy as a physical phenomenon._[2]