Definition: The ionosphere is a region of space above Earth's atmosphere where electromagnetic waves, such as radio and microwave signals, can be received by satellites. The ionosphere is the outermost layer of the Earth's atmosphere, extending from about 20 to 100 kilometers (12 to 64 miles) above the surface. It contains a variety of charged particles, including electrons, ions, and atoms, that are responsible for transmitting signals between the Earth and space.
The ionosphere
ionosphere