When you look up into the sky, what do you see?
Mostly, you’ll see a portion of the 5,000 stars that humans can see with the naked eye. But with trillions upon trillions of total stars in the universe, what we can see is only a fraction of the full picture.
What galaxy is Earth in, anyway — and where is it in relation to the rest of the universe? You might know that we’re in the Milky Way galaxy, but what does that really mean? And within that galaxy, where exactly are we located?
The mysteries of the universe aren’t all as mysterious as they seem. Although there’s a lot we still don’t know, science has also taught us a lot about our place in the universe. Ready to learn where we’re at? Here’s your road map to the universe and how Earth fits into this vast cosmos.
The Solar System
Let’s start on Earth. If we expand outward from our home planet, we’ll first find that we’re a part of a solar system that we share with seven other planets orbiting the same sun.
In addition to the other planets, our solar system also has other celestial bodies, like comets, asteroids, and dwarf planets. But all of these bodies share one thing: they orbit the sun. And within this solar system, Earth is the third-farthest planet from our sun.
The Orion Arm
The solar system might not sound too revolutionary. After all, most of us learned about the planets back in grade school. But what happens when we zoom out a bit?
The next place you need to know about is the Orion Arm. This is one of the “arms” of our galaxy, the spiral-shaped Milky Way. Our solar system sits in this arm, closer to the edge of the galaxy than to the center of it.
All spiral-shaped galaxies have “arms,” which stretch out from the middle of the galaxy. Scientists still struggle to understand exactly how our galaxy and our Orion Arm are shaped, since it’s hard to observe something from inside it. Still, this tells us something important about our place within the galaxy.
The Milky Way
If you look into the sky on a clear night, you can see the Milky Way.
From our perspective, the galaxy looks like a milky-white band across the sky (hence the name). But that white color actually comes from the vast number of stars within the galaxy.
Of course, all of the stars you can see in the night sky are also part of the Milky Way. In fact, without a telescope, the only thing you can see in the sky outside of the Milky Way is the faint outline of the Andromeda Galaxy.
Although you can’t clearly see all the stars in our galaxy, you can still see enough of them that if you want to, you can give one a name — read more here. But beyond those visible stars are countless others that we can’t fully see, but that still light up the sky.
When you look at the outline of the Milky Way in the sky, you’re actually looking at the center, or brightest part, of the galaxy. The billions of indistinct stars in that galaxy show up as a milky blur in the sky.
You also can’t always see the Milky Way in the sky. Its position relative to people on the ground depends on the rotation of the Earth. So, just like the moon and sun, the Milky Way rises and sets.
The Local Group
Once you move outside of the galaxy, you enter territory that’s often not covered in grade-school science class. Most people can easily answer “What galaxy is Earth in?” But what comes beyond that?
The Milky Way is part of a group of galaxies simply called the Local Group. This group contains over 50 galaxies. Andromeda is the largest, and the Milky Way is the second-largest. Most of the other galaxies are dwarf galaxies.
The Virgo Supercluster
The Local Group is incredibly large. Humans struggle to comprehend the full size of a single galaxy, much less a group of them. However, our Local Group sits on the edge of an even bigger group of galaxies, called the Virgo Supercluster.
Most galaxies reside in clusters or groups, held together by gravity. A small group like the Local Group is often just one part of a bigger one, like the Virgo Supercluster. A “supercluster” simply brings many of these smaller groups or clusters together.
The Virgo Supercluster is massive. But just a few years ago, scientists discovered that it was part of still another, even larger supercluster.
This “ultimate supercluster” is called Laniakea, a Hawaiian word that means “immeasurable heavens.” This cluster has around 100,000 galaxies and spans an incredible 500 million light-years.
But the universe doesn’t stop there. Laniakea is only one of many more superclusters like it, such as the Perseus-Pisces supercluster that it borders.
Basically, as far as we know, the universe is made up of these superclusters of gravity-linked galaxies, and the voids between them. If that doesn’t give you a sense of how vast space really is, nothing will!
What Galaxy Is Earth in — and What to Do with the Answer?
Now, you can see that answering “What galaxy is Earth in?” gives us just a tiny bit of knowledge about our place within the universe. On the cosmic scale, the Milky Way is actually a very small piece.
With superclusters upon superclusters making up space, we’ve still got a lot to learn. Still, what we know so far is fascinating. And new discoveries, like the Laniakea Supercluster, continue to illuminate the universe bit by bit.
There’s nothing like looking at the big picture to give you some perspective. Just thinking about the scope of the universe might inspire you to live your life to the fullest. For inspiration, make sure to check out our Self Improvement section regularly to learn how to own your place in the universe!