Once upon a time, Scientists believed that all the Stars in the night sky were part of one giant Group.
In 1917, a gentleman named Thomas Wright suggested that there might be other such groups of stars. A thought that was later proved by astronomers to be true.
And thus, Galaxies were born!
Are you one of those people who have forever been fascinated by the objects in the Night Sky? In this article you will find the answers to questions like ‘What is the largest Galaxy in the Universe?’, to ‘How many Galaxies are there in the Universe?’
It might be a good idea to begin, by taking a peek into that Knowledge Telescope, and answering the question ‘What is a Galaxy?’
A Galaxy: What it is
What is a Galaxy? Simply put, it is a group of Stars and other Space stuff. The stars in galaxies tend to spin around a centre of high gravity, much like the planets in our Solar System orbit around the Sun.
As big as galaxies might be, they are usually separated by large areas of empty Space. Scientists believe that there are over 100 billion galaxies.
Cool Fact: Galaxies are huge in themselves, and can contain trillions of Stars!
Types of Galaxies in the Universe
Scientists usually characterise Galaxies based on their aspects, like shapes and physical features.
Here are the established Types of Galaxies in the Universe.
As the name suggests, these galaxies are characterized by their distinct spiral arms. They are surrounded by halos, star clusters and dark matter. These are invisible things that do not emit or reflect light, but still have a gravitational pull on other matter.
Example: Our very own Milky Way!
These have shapes that range from oval, to completely round. Unlike spiral galaxies, they usually contain little gas and dust. The stars here are older than the ones in spiral galaxies.
Example: Cygnus A
As the name suggests, these galaxies have no shape in particular. They do not have any known components the erstwhile-discussed galaxies have. Like spirals and disks. According to NASA, what makes irregular galaxies unique, is the interactions they might have had in the past with other galaxies.
Example: The Large and Small Magellanic Clouds
Names of Galaxies in the Universe
When we name something, we bequeath it with a sense of Identity!
Here are some names of Galaxies in the Universe that make those galaxies come alive in our eyes.
This one’s a spiral galaxy, around 2.5 million Light Years from the Earth. The nearest major Galaxy to the Milky Way.
This galaxy appears to rotate backwards!
Black Eye Galaxy
Constellation: Corna Berenices
The stunning dark band of dust in front of the galaxy’s dark nucleus, lends it the nickname ‘Black Eye.’
Constellation: Ursa Major
This one’s named after its inventor, Johann Elert Bode, who discovered it in 1774.
The appearance of this galaxy is akin to that of a spiked cartwheel!
Constellation: Serpent’s Caput
Yet another galaxy, named after its inventor. In this case, Art Hoag.
Constellation: Cygneus and Cypheus
This one derives its name from its bright and spotty appearance.
How can we forget our very own galaxy? Its dreamlike appearance from the Earth is that of a Band of Light.
Interesting Galaxy Facts
If you’re hungry for even more information about Galaxies, you’re in for a stroke of luck!
In this section we have compiled some interesting galaxy facts, to provide you with an ‘Out-of-the World’ ride!
- The Biggest of the Big. The largest galaxy in the Universe is IC 1101. It has a mass of about 100 trillion Stars!
- The Milky Way will one day merge with the Andromeda Galaxy. This will take around 4 billion years, and the resultant galaxy will be an ellipsoid named ‘Milkomeda.’
- Some galaxies are known as ‘Starburst Galaxies.’ The unusual amount of gas and dust that they have, leads to a high rate of star production.
- There are more galaxies in the known Universe, than you can imagine. If you have ever wondered how many galaxies there are in the universe, this one’s for you. There might be as many as two trillion galaxies in the observable universe!
- Most galaxies have black holes. These lie at the centre of the galaxies, and are supper massive in size.
- The capitalized ‘Galaxy’ is used to refer to the Milky Way. This is done to distinguish it from the billions of other galaxies in the universe.
- Galaxies can collide with each other. When such massive events take place, several interesting things can happen. Such as, the formation of new stars.
- The Milky Way has two dwarf galaxies as its neighbours. The study of these galaxies, known as The Magellanic Clouds, is helping astronomers understand how galaxies are formed.
- The word ‘Galaxy’ is derived from a Greek word. The word is ‘Galaxias’, and it means ‘Milky.’ This is a reference to our very own Milky Way.
- Most galaxies in the Universe are really smaller, Dwarf Galaxies. These are roughly one hundredth the size of The Milky Way, and have only a few billion stars.
- They are held together by Gravity. It is the force of Gravity that keeps a galaxy together. Without gravity, the stars of a galaxy would fly off into Space!
- The command ‘Okay Google’, is a tribute to a book! It pays homage to a famous line in the bestselling novel ‘The Hitchhiker’s Guide to the Galaxy.’
- The Milky Way completes a rotation every 200 million years. One full revolution ago, dinosaurs ruled the Earth.
At EuroKids we are all for encouraging children to learn as much as they can about Galaxies. Right from a tender age, children ask all sorts of questions about the Night Sky. Learning more about galaxies, will not only sharpen their Knowledge, but also encourage their sense of Wonder.