Exosphere

 What exactly is the exosphere?

The exosphere is the Earth's atmosphere's outermost layer.

The topmost layer

The exosphere is our atmosphere's

outermost layer. "Exo" means "outside," and it is the same prefix used to describe insects with a hard shell or "exoskeleton" on the outside of their bodies, such as grasshoppers.

The exosphere is the outermost region of our atmosphere. This layer is what separates the rest of the atmosphere from space. It is approximately 6,200 miles (10,000 kilometres) thick. That's almost as big as the Earth. The exosphere is extremely vast. That means you have to be very far away from Earth to reach outer space.

The exosphere contains gases such as hydrogen and helium, but they are widely dispersed. There is a lot of white space between them. It's very cold and there's no air to breathe.