Have you ever wondered…
When you look up in the stars, do you ever see a milky white band, stretching across the sky? This white band is called the Milky Way, and it is the galaxy that we make our home in.
Scattered across the universe are many different shaped star clusters called galaxies. A galaxy is made up of gas, dust, stars, and black holes, and they are held together by gravity. If galaxies get too close, they collide, but the solar systems are so spread out inside them that you won't feel a thing.
The type of galaxy that we live in is called a barred spiral galaxy that has four main spiral arms. It was very hard to tell what our galaxy looked like until very recently because our Solar System is embedded inside it! But there are many more galaxies besides our own.
We are not able to count how many galaxies there are because the universe is so big, but we know that every single galaxy is different. Different sizes, shapes and colors. The types of galaxies are a spiral galaxy, which the shape is obvious, an irregular galaxy, which is a galaxy that is found in weird shapes and sizes. Lastly, there is an elliptical galaxy, which is a circle of bright light.
If galaxies get too close, they collide, but the solar systems are so spread out inside them that you won't feel a thing.
The Milky Way Galaxy is named for its look. The white haze that our galaxy produces looks like spilled milk. The stars make cloudy patches in the sky. All the stars we see at night are only a tiny fraction of all the stars in our galaxy.
Our galaxy is CRAZY big! It is 120,000 light years long and 1,000 light years thick! But there are many more galaxies that are enormous compared to ours! The Andromeda Galaxy is our closest galactic neighbor and is very much like our own. It is also a barred spiral galaxy and could probably hold life forms.
Surprisingly, only 10% of galaxies are able to support such complex life as us. Stellar explosions in some galaxies, also known as gamma ray bursts, would wipe out all life more complex than microbes. There is a low brightness in some galaxies which means that there are not that many heavy elements. Heavy elements are needed to make heavy rock formations like earth.
We don’t actually know how the first galaxies were formed , but super smart scientists have came up with a few conclusions. The first is a very popular theory called The Big Bang Theory. Yes, I know, you may be thinking of the televisions show, but that is not what we are talking about. The Big Bang Theory is a theory in which every bit of mass in the universe started with a gigantic explosion. Another is the universe was always there and that galaxies were formed by small clumps of matter clumped together and formed modern-day galaxies.
Have you ever heard of dark matter? Dark matter is a mysterious object, no not object, more like thing, that can not be seen to the human eye. It can’t be seen by anything actually, not even the highest technology. But even so, scientists are positive it’s there. It affects galaxies and galaxy clusters. Stars at the edge of a spinning galaxy should travel slower than those near regular matter, or baryonic matter. But they travel at the same speed no matter where they are in the galaxy. Dark matter explains this . There is an invisible gravity making them travel the same speed as anything else in the galaxy.
The universe and its galaxies are still quite confusing to scientists but we are making discoveries that are helping us understand more and more about our universe. I hope some of you will help support these discoveries and thanks for reading!
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