Atmospheres

 

Some planets and moons are covered in a thin layer of gases. This is called an Atmosphere.

Not all atmospheres are the same. In fact, Earth's atmosphere is the only one we have found that we can breathe.

Atmospheres are held down to the surface by gravity, so small planets and moons usually do not have them.

Although we cannot normally see our atmosphere, we can certainly feel it when we struggle to school on a windy day.