What is the earth's lonosphere?

Answer 1

The area extending from 80km above the eart's surface to the edge of the atmosphere--the second-most outer layer, second only to the exosphere. Here free electrons can exist for short periods of time before they are captured by a nearby positive ion. The existence of charged particles at this altitude and above, signals the beginning of the ionosphere a region having the properties of a gas and of a plasma.

Answer 2

The Earth's ionosphere is a region of the upper atmosphere, extending from about 48 kilometers to 965 kilometers above the Earth's surface, that is ionized by solar and cosmic radiation. It plays a crucial role in radio communications and reflects radio waves back to Earth, enabling long-distance communication. The ionosphere also helps protect us from harmful solar radiation by absorbing and dispersing it.