Understanding Galaxies: Types, Shapes, and Formation Explained

KOMPAS.com – The universe is everything that exists. It includes all of space, as well as all the matter and energy contained in outer space.

Even time is also part of the universe, and galaxies are one part of the universe.

There are many galaxies in the universe, one of which is the Milky Way galaxy in which there is Earth where humans live.

Also read: 7 Rarely Known Facts about the Planet Neptune, the Ice Giant in the Solar System

So, what is a galaxy? Check out the following explanation.

Understanding galaxies

Quoted from the Encyclopedia Britannica page, a galaxy is a system of stars and interstellar material that forms the universe.

Galaxies consist of dust, gas, dark matter, and millions to trillions of stars held together by gravity.

Almost all galaxies were born soon after the universe was created, then these galaxies were scattered throughout space.

Also read: The reason Pluto was removed from the list of planets in the solar system, why?

The first stars in the universe appeared about 180 million years after the big bang, the moment that marked the origin of the universe.

Gravity then formed the early galaxies when the universe was 400 million years old.

The shapes of galaxies differ from one another, with variations resulting from the way the systems form and then evolve.

Also read: Not Just Humans, These Are 5 Animals That Have Successfully Gone to Space

Types of galaxies

Reporting from the National Geographic page, galaxies can be grouped into four main types, namely as follows:

1. Spiral galaxy

Spiral galaxies have a flat rotating disk with a central bulge surrounded by spiral arms.

The rotating movement at a speed of hundreds of kilometers per second can cause the material in the disk to take a distinctive spiral shape, like a cosmic pinwheel.

The Milky Way, where the Earth and its solar system are located, is an example of a spiral galaxy. It has a starry linear bar at its center.

Also read: Why are the planets in the Solar System round? The following is the explanation

2. Elliptical galaxy

Elliptical galaxies are generally round but can stretch longer on one axis than the other.

The largest known galaxies in the universe, giant elliptical galaxies, can accommodate up to a trillion stars and stretch as far as two million light years.

However, this type of galaxy can also be small, so it is called a dwarf elliptical galaxy. This galaxy has little dust and interstellar material.

Also read: Called Earth’s twin, here are 5 interesting facts about the planet Venus

3. Lenticular galaxies

Lenticular galaxies, such as the Sombrero Galaxy, have a shape somewhere between an elliptical and a spiral galaxy. It is called “lenticular” because it resembles a lens.

Like spiral galaxies, this type has a thin, rotating disk of stars and a central bulge, but no spiral arms.

And like elliptical galaxies, they have little dust and interstellar matter, and appear to form more often in densely populated regions of space.

Also read: How does a lunar eclipse occur? The following is the explanation

4. Irregular galaxies

Irregular galaxies, such as the Large and Small Magellanic Clouds that flank the Milky Way galaxy, appear to have no clear shape.

Often because these galaxies are under the gravitational influence of other nearby galaxies.

They are full of gas and dust, making them great breeding grounds for the formation of new stars.

Get selected news updates and breaking news every day from Kompas.com. Let’s join the Telegram Group “Kompas.com News Update”, by clicking the link https://t.me/kompascomupdate, then join. You must install the Telegram application first on your cellphone.

2024-03-01 13:45:00
#Galaxies #Star #Systems #Form #Universe #Kompas.com