Editing Altitude (section)

===Atmospheric layers===
{{main|Atmospheric layers}}
The [[Earth's atmosphere]] is divided into several altitude regions. These regions start and finish at varying heights depending on season and distance from the poles.  The altitudes stated below are averages:<ref>{{cite web | title=Layers of the Atmosphere |work=JetStream, the National Weather Service Online Weather School | publisher=National Weather Service | url=http://www.srh.noaa.gov/srh/jetstream/atmos/layers.htm | access-date=22 December 2005| archive-url= https://web.archive.org/web/20051219190158/http://www.srh.noaa.gov/srh/jetstream/atmos/layers.htm| archive-date= 19 December 2005 | url-status= live}}</ref>
* [[Troposphere]]: surface to {{convert|8000|m|mi}} at the poles, {{convert|18000|m|miles}} at the [[Equator]], ending at the Tropopause
* [[Stratosphere]]: Troposphere to {{convert|50|km|mi}}
* [[Mesosphere]]: Stratosphere to {{convert|85|km|mi}}
* [[Thermosphere]]: Mesosphere to {{convert|675|km|mi}}
* [[Exosphere]]: Thermosphere to {{convert|10000|km|mi}}

The [[Kármán line]], at an altitude of {{convert|100|km|mi}} above [[sea level]], by convention defines represents the demarcation between the atmosphere and [[outer space|space]].<ref>{{cite web|url=http://www.fai.org/icare-records/100km-altitude-boundary-for-astronautics|title=The 100&nbsp;km Boundary for Astronautics|author=Dr. S. Sanz Fernández de Córdoba|publisher=[[Fédération Aéronautique Internationale]]|date=24 June 2004|archive-url=https://web.archive.org/web/20110809093537/http://www.fai.org/astronautics/100km.asp|archive-date=9 August 2011}}</ref> The thermosphere and exosphere (along with the higher parts of the mesosphere) are regions of the atmosphere that are conventionally defined as space.