Sometimes the sky can seem a little two dimensional, but there's a lot more going on up there than you think.

And our sky might just be the reason for life on Earth.

Why do we need the sky?

Our big, beautiful blue sky is actually composed of five distinct layers that make up our atmosphere.

Those layers are filled with different combinations of elements like oxygen, nitrogen, carbon dioxide, and lots more.

It's like a layer cake that keeps air in our lungs and protects us from being blasted by the sun's harmful radiation.

The layer we call home is called the troposphere.

It's where we breathe, where storms build and dissolve, and where nearly all the clouds form.

It's the smallest part of the atmosphere, but also the most dense, thanks to the weight of the layers above it.

Climb about four miles up and the stratosphere begins.

This region is home to the ozone layer, a concentration of gas responsible for absorbing the sun's harmful ultraviolet radiation before it gets to us.

Even higher is the mesosphere, starting about 31 miles above Earth.

Too thin to do much, but just thick enough to matter.

When meteors come down from space it's the mesosphere that catches them and slows their entry, turning them into shooting stars we can see from the ground.

Once we get to the next layer, the thermosphere, things start getting weird.

53 miles up, the thermosphere is the first layer that catches high energy radiation from the sun.

Because of this, it has a much wider temperature swing than other layers, from as low as -184°F, all the way up to 3600 degrees at the top.

The last layer before we get to space is the exosphere, 375 miles up from the surface of the Earth.

This is where satellites can safely orbit and where atoms and molecules escape into space.

That's a lot to take in.

So let's think about it this way.

It may look like a big expanse of nothingness up above us, but our sky is doing a lot of work for us behind the scenes.

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