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What is inside the Earth? |
Our Planet
When you look down at the ground, what do you see? Maybe some grass, pavement, or some dirt. What’s under that? Probably some dirt and rocks. But what is underneath all of that?
It’s about 4000 miles to the center of the Earth and there are a lot of layers between it and the ground we stand on!
The top layer of the Earth is called the Crust. It’s rocky and mostly cool. (Although, every now and then a volcano will make the temperature rise!) The rocks that make up the crust are the types we’re pretty familiar with, like the stones and pebbles you might see on a walk in the woods.
The crust is actually the thinnest layer of the Earth, but it’s over 20 miles thick in most parts! That’s about the same distance you’ll cover in a car on the highway in 20 minutes, except this distance is straight down!
Below the crust is the Mantle. Most of the material of the Earth is in this layer. It’s made of rocks too, but the crushing pressure of the Earth’s interior has turned the rocks into a very slow-moving material, almost like a plastic! The mantle is about 1,800 miles from top to bottom and it’s very hot!
The next layer is the Outer Core, and it is also very hot there—so hot that the metals iron and nickel that make it up have mostly melted. And then, at the very center of the Earth, is the Inner Core. The pull of gravity is so strong here that the iron that makes up most of this layer has been pulled into a solid ball, despite the heat! Together, the two layers of the core are about the size of the planet Mars!
Digging a Hole to China
You may have seen this idea in old cartoons. Someone will dig a hole so deep that they go all the way through the Earth and come out on the other side! China is pretty much on the exact opposite side of the world from the United States.
Knowing what you know now about the Earth and its layers. Could you dig a hole straight through the Earth? What sort of problems would you run into? The first one would probably be you getting tired! If you did manage to get through all the lose dirt, you’d hit a big layer of rock next! You’d need more than a shovel to get through that! What other obstacles would you run into?
If you can, take a look at a globe or a map. What part of the world is on the exact opposite side from where you are? Imagine what it would be like to go there. Even if you can’t dig a hole, it’s still fun to imagine. And maybe, you might even be able to take a trip there someday! You’d just have to go around the outside of the world, probably in a plane.
