Description: The ionosphere is a part of the atmosphere (above about 80 kilometers). It contains a high concentration of ions due to the high-energy part of the radiation the Earth receives from the Sun, which breaks the molecules into atoms, and then atoms into ions and electrons. The presence of the free electrons makes this region of the atmosphere a good conductor of electricity. As such, the ionosphere is able to reflect radio waves at certain wavelengths.

Related Terms:

• Atmosphere
• Electron

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".