is a region of Earth's upper atmosphere, from about 60 km (37 mi) to 1,000 km (620 mi) altitude,[3] and includes the thermosphere and parts of the mesosphere and exosphere. It is ionized by solar radiation, plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the <span>Earth</span>
