What’s inside the earth?
Could you dig a hole to the other side of the earth?
No, you couldn’t. The center of the earth is about 4,000 miles (6,400
kilometers) beneath your feet. So, it’s almost 8,000 miles (13,000
kilometers) to the other side of the earth. You couldn’t dig that far.
And for most of that distance, the earth is either solid rock or metal
so hot that it’s melted! You certainly couldn’t dig through that!
When the outside of the earth cooled, it became a kind of shell of rock.
We call this the crust. The oceans and the continents lie on top of the
crust. Beneath the oceans, the crust is about five miles (8 kilometers)
thick. Beneath the land, it is about twenty-five miles (40 kilometers)
thick.
Under the crust there is another layer of rock called the mantle. The
mantle is made of a different kind of rock than the crust. The deeper
the mantle goes, the hotter it gets. It is about 1,800 miles (2,900
kilometers) thick. At its bottom, it is hot enough to melt iron.
Beneath the mantle is a layer of melted metal— metal so hot that it’s
like thick syrup! This layer is called the outer core. Scientists think
the outer core is made of iron and nickel and is about 1,400 miles
(2,250 kilometers) thick.
In the center of the earth is the inner core. It’s a ball of hot, solid,
squeezed-together metal about 1,600 miles (2,570 kilometers) thick.
That’s what’s inside the earth.
