Editing Atmosphere (section)

==Structure of atmosphere==

===Earth===
[[File:469649main earths-atmosphere-orig full.jpg|thumb|Earth's atmosphere profile]]
The [[atmosphere of Earth]] is composed of layers with different properties, such as specific gaseous composition, temperature, and pressure.

The [[troposphere]] is the lowest layer of the atmosphere. This extends from the planetary surface to the bottom of the [[stratosphere]]. The troposphere contains 75–80% of the mass of the atmosphere,<ref name="natgeoatmosphere"/> and is the atmospheric layer wherein the weather occurs; the height of the troposphere varies between 17&nbsp;km at the equator and 7.0&nbsp;km at the poles.

The [[stratosphere]] extends from the top of the troposphere to the bottom of the [[mesosphere]], and contains the [[ozone layer]], at an altitude between 15&nbsp;km and 35&nbsp;km. It is the atmospheric layer that absorbs most of the [[ultraviolet radiation]] that Earth receives from the Sun.

The [[mesosphere]] ranges from 50&nbsp;km to 85&nbsp;km and is the layer wherein most [[meteors]] are incinerated before reaching the surface.

The [[thermosphere]] extends from an altitude of 85&nbsp;km to the base of the [[exosphere]] at 690&nbsp;km and contains the [[ionosphere]], where solar radiation ionizes the atmosphere. The density of the ionosphere is greater at short distances from the planetary surface in the daytime and decreases as the ionosphere rises at night-time, thereby allowing a greater range of radio frequencies to travel greater distances.

The [[exosphere]] begins at 690 to 1,000&nbsp;km from the surface, and extends to roughly 10,000&nbsp;km, where it interacts with the [[magnetosphere]] of Earth.