That's almost right! The ionosphere doesn't technically lie between the mesosphere and exosphere. It actually overlaps with both of them.

Here's a breakdown:

* Mesosphere: This layer is above the stratosphere and below the thermosphere. It's known for its cold temperatures and is where most meteors burn up.

* Thermosphere: This layer is above the mesosphere and below the exosphere. It's characterized by extremely high temperatures due to absorption of solar radiation.

* Exosphere: This is the outermost layer of Earth's atmosphere, where it gradually fades into outer space.

The ionosphere is defined by the presence of ionized particles, primarily created by the Sun's radiation. This ionization occurs mainly within the thermosphere, but it can extend a little bit into the lower portion of the exosphere. So, the ionosphere overlaps the thermosphere and the very bottom of the exosphere.