8
Most of our planet is made
of rock. But the planet is not
a hard, solid ball.
Earth is made of layers,
just like a birthday cake. The
top layer is called the
crust
.
Like the frosting on a cake,
Earth’scrust is thincompared
to the layers below it.
Next comes a thick layer
called the
mantle
. It contains
hot, soft rock called
magma
. Even though magma is thick, it can
flow—just like cooked oatmeal.
Earth’s sizzling-hot core has two parts. Melted metals slosh
around inside the liquid outer core. The weight of all the
overlying layers presses the inner core’s molecules close together.
So the inner core is solid.
3
Layers of Earth
