The ozone layer is that part of a planet's atmosphere which contains higher than usual concentrations of ozone. Even the small concentrations of ozone present in the ozone layer are vital to life on most planets because of the particle's ability to block ultraviolet radiation, which can be harmful to biological life.
The planet Aldea suffered damage to its ozone layer from the long-term use of its planetary defense system. The resulting radiation poisoning rendered the Aldeans sterile and threatened to destroy their civilization. (TNG: "When The Bough Breaks")
|Structure and layers of an atmosphere|
| Planetary: Troposphere • Stratosphere • Thermosphere • Exosphere |
Ozone layer • Ionosphere • Magnetosphere • Mesosphere
|Solar: Photosphere • Chromosphere • Corona|