Here's why:

* Exosphere: This is the outermost layer of Earth's atmosphere. It's extremely thin, with very few particles. Satellites orbiting Earth are generally located in this layer because there's minimal atmospheric drag, allowing them to maintain their orbits for long periods.

* Other Layers: Satellites don't exist in the lower layers of the atmosphere like the troposphere, stratosphere, or mesosphere. These layers contain much denser air, which would cause significant friction and slow down or even destroy satellites.

It's important to note that some satellites, particularly those involved in atmospheric research, might pass through lower layers of the atmosphere for brief periods, but they don't reside there permanently.